Bio

Academic Appointments


Administrative Appointments


  • Senior Research Scientist, Cancer Prevention Institute of California (2002 - Present)
  • Consulting Professor, Stanford, Dept. Health Policy & Research (2007 - Present)

Professional Education


  • Ph.D., Yale University, Epidemiology (1986)
  • BA, Johns Hopkins University, Psychology (1981)

Research & Scholarship

Current Research and Scholarly Interests


My research interests focus on nutrition and the etiology of hormonally-dependent cancers in women (most particularly breast, endometrial, and thyroid cancers). Of particular interest are the effects of phytochemicals that may reduce cancer risk, such as the isoflavones in soy foods, the lignans in whole grains, the isothiocyanates in broccoli and other cruciferous vegetables, and resveratrol in red wine and peanuts. Nutrient-gene interactions are also of interest.

Publications

Journal Articles


  • Reproductive Factors, Exogenous Hormones, and Pancreatic Cancer Risk in the CTS. American journal of epidemiology Lee, E., Horn-Ross, P. L., Rull, R. P., Neuhausen, S. L., Anton-Culver, H., Ursin, G., Henderson, K. D., Bernstein, L. 2013; 178 (9): 1403-1413

    Abstract

    Female steroid hormones are hypothesized to play a protective role in pancreatic cancer risk. However, results from epidemiologic studies that examined hormone-related exposures have been inconsistent. The California Teachers Study is a cohort study of female public school professionals that was established in 1995-1996. Of the 118,164 eligible study participants, 323 women were diagnosed with incident invasive pancreatic cancer through December 31, 2009. Multivariable Cox proportional hazards regression methods were used to estimate hazard ratios and 95% confidence intervals for the association of pancreatic cancer risk with reproductive factors and exogenous hormone use. Current users of estrogen-only therapy at baseline (1995-1996) had a lower risk of pancreatic cancer than did participants who had never used hormone therapy (hazard ratio = 0.59, 95% confidence interval: 0.42, 0.84). Use of estrogen-plus-progestin therapy was not associated with the risk of pancreatic cancer. A longer duration of oral contraceptive use (≥10 years of use compared with never use) was associated with an increased risk of cancer (hazard ratio = 1.72, 95% confidence interval: 1.19, 2.49). Reproductive factors, including age at menarche, parity, breastfeeding, and age at menopause, were not associated with pancreatic cancer risk. Our results suggest that increased estrogen exposure through estrogen-only therapy may reduce pancreatic cancer risk in women.

    View details for DOI 10.1093/aje/kwt154

    View details for PubMedID 24008905

  • Long-term and baseline recreational physical activity and risk of endometrial cancer: the California Teachers Study BRITISH JOURNAL OF CANCER Dieli-Conwright, C. M., Ma, H., Lacey, J. V., Henderson, K. D., Neuhausen, S., Horn-Ross, P. L., Deapen, D., Sullivan-Halley, J., Bernstein, L. 2013; 109 (3): 761-768

    Abstract

    Background:Physical activity may be associated with decreasing endometrial cancer risk; it remains unclear whether the association is modified by body size.Methods:Among 93 888 eligible California Teachers Study participants, 976 were diagnosed with incident endometrial cancer between 1995-1996 and 2007. Cox proportional hazards regression methods were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for endometrial cancer associated with long-term (high school through age 54 years) and baseline (3 years prior to joining the cohort) strenuous and moderate recreational physical activity, overall and by body size.Results:Increased baseline strenuous recreational physical activity was associated with decreased endometrial cancer risk (Ptrend=0.006) with approximately 25% lower risk among women exercising >3 h per week per year than among those exercising <1/2 h per week per year (RR, 0.76; 95% CI, 0.63-0.92). This inverse association was observed among overweight/obese women (body mass index ≥25 kg m(-2); Ptrend=0.006), but not among thinner women (Ptrend=0.12). Baseline moderate activity was associated with lower risk among overweight/obese women.Conclusion:Increasing physical activity, particularly strenuous activity, may be a lifestyle change that overweight and obese women can implement to reduce their endometrial cancer risk.British Journal of Cancer advance online publication 16 July 2013; doi:10.1038/bjc.2013.61 www.bjcancer.com.

    View details for DOI 10.1038/bjc.2013.61

    View details for Web of Science ID 000322824700032

    View details for PubMedID 23860525

  • Type I and II endometrial cancers: have they different risk factors? Journal of clinical oncology Setiawan, V. W., Yang, H. P., Pike, M. C., McCann, S. E., Yu, H., Xiang, Y., Wolk, A., Wentzensen, N., Weiss, N. S., Webb, P. M., van den Brandt, P. A., Van de Vijver, K., Thompson, P. J., Strom, B. L., Spurdle, A. B., Soslow, R. A., Shu, X., Schairer, C., Sacerdote, C., Rohan, T. E., Robien, K., Risch, H. A., Ricceri, F., Rebbeck, T. R., Rastogi, R., Prescott, J., Polidoro, S., Park, Y., Olson, S. H., Moysich, K. B., Miller, A. B., McCullough, M. L., Matsuno, R. K., Magliocco, A. M., Lurie, G., Lu, L., Lissowska, J., Liang, X., Lacey, J. V., Kolonel, L. N., Henderson, B. E., Hankinson, S. E., Håkansson, N., Goodman, M. T., Gaudet, M. M., Garcia-Closas, M., Friedenreich, C. M., Freudenheim, J. L., Doherty, J., De Vivo, I., Courneya, K. S., Cook, L. S., Chen, C., Cerhan, J. R., Cai, H., Brinton, L. A., Bernstein, L., Anderson, K. E., Anton-Culver, H., Schouten, L. J., Horn-Ross, P. L. 2013; 31 (20): 2607-2618

    Abstract

    PURPOSEEndometrial cancers have long been divided into estrogen-dependent type I and the less common clinically aggressive estrogen-independent type II. Little is known about risk factors for type II tumors because most studies lack sufficient cases to study these much less common tumors separately. We examined whether so-called classical endometrial cancer risk factors also influence the risk of type II tumors. PATIENTS AND METHODSIndividual-level data from 10 cohort and 14 case-control studies from the Epidemiology of Endometrial Cancer Consortium were pooled. A total of 14,069 endometrial cancer cases and 35,312 controls were included. We classified endometrioid (n = 7,246), adenocarcinoma not otherwise specified (n = 4,830), and adenocarcinoma with squamous differentiation (n = 777) as type I tumors and serous (n = 508) and mixed cell (n = 346) as type II tumors. RESULTS: odds ratio (OR) per 2 kg/m(2) increase was 1.20 (95% CI, 1.19 to 1.21) for type I and 1.12 (95% CI, 1.09 to 1.14) for type II tumors (Pheterogeneity < .0001). Risk factor patterns for high-grade endometrioid tumors and type II tumors were similar. CONCLUSIONThe results of this pooled analysis suggest that the two endometrial cancer types share many common etiologic factors. The etiology of type II tumors may, therefore, not be completely estrogen independent, as previously believed.

    View details for DOI 10.1200/JCO.2012.48.2596

    View details for PubMedID 23733771

  • Determinants and within-person variability of urinary cadmium concentrations among women in northern California. Environmental health perspectives Gunier, R. B., Horn-Ross, P. L., Canchola, A. J., Duffy, C. N., Reynolds, P., Hertz, A., Garcia, E., Rull, R. P. 2013; 121 (6): 643-649

    Abstract

    Background: Cadmium (Cd) is a toxic metal associated with increased morbidity and mortality. Urinary Cd (U-Cd) concentration is considered a biomarker of long-term exposure.Objectives: Our objectives were to evaluate the within-person correlation among repeat samples and to identify predictors of U-Cd concentrations.Methods: U-Cd concentrations (micrograms per liter) were measured in 24-hr urine samples collected from 296 women enrolled in the California Teachers Study in 2000 and a second 24-hr sample collected 3-9 months later from 141 of the participants. Lifestyle and sociodemographic characteristics were obtained via questionnaires. The Total Diet Study database was used to quantify dietary cadmium intake based on a food frequency questionnaire. We estimated environmental cadmium emissions near participants' residences using a geographic information system.Results: The geometric mean U-Cd concentration was 0.27 µg/L and the range was 0.1-3.6 µg/L. The intraclass correlation among repeat samples from an individual was 0.50. The use of a single 24-hr urine specimen to characterize Cd exposure in a case-control study would result in an observed odds ratio of 1.4 for a true odds ratio of 2.0. U-Cd concentration increased with creatinine, age, and lifetime pack-years of smoking among ever smokers or lifetime intensity-years of passive smoking among nonsmokers, whereas it decreased with greater alcohol consumption and number of previous pregnancies. These factors explained 42-44% of the variability in U-Cd concentrations.Conclusion: U-Cd levels varied with several individual characteristics, and a single measurement of U-Cd in a 24-hr sample did not accurately reflect medium- to long-term body burden.

    View details for DOI 10.1289/ehp.1205524

    View details for PubMedID 23552363

  • The etiology of uterine sarcomas: a pooled analysis of the epidemiology of endometrial cancer consortium BRITISH JOURNAL OF CANCER Felix, A. S., Cook, L. S., Gaudet, M. M., Rohan, T. E., Schouten, L. J., Setiawan, V. W., Wise, L. A., Anderson, K. E., Bernstein, L., De Vivo, I., Friedenreich, C. M., Gapstur, S. M., Goldbohm, R. A., Henderson, B., Horn-Ross, P. L., Kolonel, L., Lacey, J. V., Liang, X., Lissowska, J., Magliocco, A., McCullough, M. L., Miller, A. B., Olson, S. H., Palmer, J. R., Park, Y., Patel, A. V., Prescott, J., Rastogi, R., Robien, K., Rosenberg, L., Schairer, C., Shu, X. O., van den Brandt, P. A., Virkus, R. A., Wentzensen, N., Xiang, Y., Xu, W., Yang, H. P., Brinton, L. A. 2013; 108 (3): 727-734

    Abstract

    Uterine sarcomas are characterised by early age at diagnosis, poor prognosis, and higher incidence among Black compared with White women, but their aetiology is poorly understood. Therefore, we performed a pooled analysis of data collected in the Epidemiology of Endometrial Cancer Consortium. We also examined risk factor associations for malignant mixed mullerian tumours (MMMTs) and endometrioid endometrial carcinomas (EECs) for comparison purposes.We pooled data on 229 uterine sarcomas, 244 MMMTs, 7623 EEC cases, and 28,829 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) for risk factors associated with uterine sarcoma, MMMT, and EEC were estimated with polytomous logistic regression. We also examined associations between epidemiological factors and histological subtypes of uterine sarcoma.Significant risk factors for uterine sarcoma included obesity (body mass index (BMI)?30 vs BMI<25 kg m(-2) (OR: 1.73, 95% CI: 1.22-2.46), P-trend=0.008) and history of diabetes (OR: 2.33, 95% CI: 1.41-3.83). Older age at menarche was inversely associated with uterine sarcoma risk (?15 years vs <11 years (OR: 0.70, 95% CI: 0.34-1.44), P-trend: 0.04). BMI was significantly, but less strongly related to uterine sarcomas compared with EECs (OR: 3.03, 95% CI: 2.82-3.26) or MMMTs (OR: 2.25, 95% CI: 1.60-3.15, P-heterogeneity=0.01).In the largest aetiological study of uterine sarcomas, associations between menstrual, hormonal, and anthropometric risk factors and uterine sarcoma were similar to those identified for EEC. Further exploration of factors that might explain patterns of age- and race-specific incidence rates for uterine sarcoma are needed.

    View details for DOI 10.1038/bjc.2013.2

    View details for Web of Science ID 000316523400035

    View details for PubMedID 23348519

  • Fruit and Vegetable Intake and Risk of Breast Cancer by Hormone Receptor Status JNCI-JOURNAL OF THE NATIONAL CANCER INSTITUTE Jung, S., Spiegelman, D., Baglietto, L., Bernstein, L., Boggs, D. A., van den Brandt, P. A., Buring, J. E., Cerhan, J. R., Gaudet, M. M., Giles, G. G., Goodman, G., Hakansson, N., Hankinson, S. E., Helzlsouer, K., Horn-Ross, P. L., Inoue, M., Krogh, V., Lof, M., McCullough, M. L., Miller, A. B., Neuhouser, M. L., Palmer, J. R., Park, Y., Robien, K., Rohan, T. E., Scarmo, S., Schairer, C., Schouten, L. J., Shikany, J. M., Sieri, S., Tsugane, S., Visvanathan, K., Weiderpass, E., Willett, W. C., Wolk, A., Zeleniuch-Jacquotte, A., Zhang, S. M., Zhang, X., Ziegler, R. G., Smith-Warner, S. A. 2013; 105 (3): 219-236

    Abstract

    Estrogen receptor-negative (ER(-)) breast cancer has few known or modifiable risk factors. Because ER(-) tumors account for only 15% to 20% of breast cancers, large pooled analyses are necessary to evaluate precisely the suspected inverse association between fruit and vegetable intake and risk of ER(-) breast cancer.Among 993 466 women followed for 11 to 20 years in 20 cohort studies, we documented 19 869 estrogen receptor positive (ER(+)) and 4821 ER(-) breast cancers. We calculated study-specific multivariable relative risks (RRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression analyses and then combined them using a random-effects model. All statistical tests were two-sided.Total fruit and vegetable intake was statistically significantly inversely associated with risk of ER(-) breast cancer but not with risk of breast cancer overall or of ER(+) tumors. The inverse association for ER(-) tumors was observed primarily for vegetable consumption. The pooled relative risks comparing the highest vs lowest quintile of total vegetable consumption were 0.82 (95% CI = 0.74 to 0.90) for ER(-) breast cancer and 1.04 (95% CI = 0.97 to 1.11) for ER(+) breast cancer (P (common-effects) by ER status < .001). Total fruit consumption was non-statistically significantly associated with risk of ER(-) breast cancer (pooled multivariable RR comparing the highest vs lowest quintile = 0.94, 95% CI = 0.85 to 1.04).We observed no association between total fruit and vegetable intake and risk of overall breast cancer. However, vegetable consumption was inversely associated with risk of ER(-) breast cancer in our large pooled analyses.

    View details for DOI 10.1093/jnci/djs635

    View details for Web of Science ID 000314865300009

    View details for PubMedID 23349252

  • Recreational physical activity and risk of papillary thyroid cancer among women in the California Teachers Study CANCER EPIDEMIOLOGY Cash, S. W., Ma, H., Horn-Ross, P. L., Reynolds, P., Canchola, A. J., Sullivan-Halley, J., Beresford, S. A., Neuhouser, M. L., Vaughan, T. L., Heagerty, P. J., Bernstein, L. 2013; 37 (1): 46-53

    Abstract

    Little is known about the relationship between physical activity and thyroid cancer risk, and few cohort data on this association exist. Thus, the present study aimed to prospectively examine long-term activity and risk of papillary thyroid cancer among women.116,939 women in the California Teachers Study, aged 22-79 years with no history of thyroid cancer at cohort entry, were followed from 1995-1996 through 2009; 275 were diagnosed with invasive papillary thyroid cancer. Cox proportional-hazards regression provided relative risk (RR) estimates and 95% confidence intervals (CI) for associations between thyroid cancer and combined strenuous and moderate recreational physical activity both in the long-term (high school through age 54 years or current age if younger than 54 years) and recently (during the three years prior to joining the cohort).Overall, women whose long-term recreational physical activity averaged at least 5.5 MET-hours/week (i.e. were active) had a non-significant 23% lower risk of papillary thyroid cancer than inactive women (RR = 0.77, 95% CI: 0.57, 1.04). RR estimates were stronger among normal weight or underweight women (body mass index, BMI<25.0 kg/m(2), trend p = 0.03) than among overweight or obese women (trend p = 0.35; homogeneity-of-trends p = 0.03). A similar pattern of risk was observed for recent activity (BMI<25 kg/m(2), trend p = 0.11; BMI?25 kg/m(2), trend p = 0.16; homogeneity-of-trends p = 0.04). Associations for long-term activity did not appear to be driven by activity in any particular life period (e.g. youth, adulthood).Long-term physical activity may reduce papillary thyroid cancer risk among normal weight and underweight women.

    View details for DOI 10.1016/j.canep.2012.09.003

    View details for Web of Science ID 000314755900010

    View details for PubMedID 23116823

  • Alcohol Consumption and Breast Cancer Risk Among Postmenopausal Women Following the Cessation of Hormone Therapy Use: The California Teachers Study CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Horn-Ross, P. L., Canchola, A. J., Bernstein, L., Clarke, C. A., Lacey, J. V., Neuhausen, S. L., Reynolds, P., Ursin, G. 2012; 21 (11): 2006-2013

    Abstract

    Alcohol consumption increases breast cancer risk, but its effect may be modified by hormone therapy (HT) use, such that exposure to both may be synergistic. Because many women stopped taking HT after mid-2002, it is important to quantify risks associated with alcohol consumption in the context of HT cessation, as these risks may be more relevant to cancer prevention efforts today.Among 40,680 eligible postmenopausal California Teachers Study cohort participants, 660 were diagnosed with invasive breast cancer before 2010. Multivariate Cox proportional hazards regression models were used to estimate relative risks (RR) and 95% confidence intervals (CI).Increased breast cancer risk associated with alcohol consumption was observed among postmenopausal women who were current HT users [RR, 1.60; 95% confidence interval (CI), 1.13-2.26 and RR, 2.11; 95% CI, 1.41-3.15 for <20 and ?20 g/d of alcohol], with risks being similar by HT preparation. Alcohol did not increase risk among women who had stopped using HT within 3 years or 3 to 4 years before completing the follow-up questionnaire or in the more distant past. Results were similar for estrogen receptor positive (ER+) and ER+PR+ progesterone receptors positive (PR+) tumors; while power was limited, no increase in risk was observed for ER- tumors.Following the cessation of HT use, alcohol consumption is not significantly associated with breast cancer risk, although a nonsignificant increased risk was observed among women who never used HT.Our findings confirm that concurrent exposure to HT and alcohol has a substantial adverse impact on breast cancer risk. However, after HT cessation, this risk is reduced.

    View details for DOI 10.1158/1055-9965.EPI-12-0418

    View details for Web of Science ID 000310931700014

    View details for PubMedID 22832206

  • Intake of Fruits and Vegetables and Risk of Pancreatic Cancer in a Pooled Analysis of 14 Cohort Studies AMERICAN JOURNAL OF EPIDEMIOLOGY Koushik, A., Spiegelman, D., Albanes, D., Anderson, K. E., Bernstein, L., van den Brandt, P. A., Bergkvist, L., English, D. R., Freudenheim, J. L., Fuchs, C. S., Genkinger, J. M., Giles, G. G., Goldbohm, R. A., Horn-Ross, P. L., Mannisto, S., McCullough, M. L., Millen, A. E., Miller, A. B., Robien, K., Rohan, T. E., Schatzkin, A., Shikany, J. M., Stolzenberg-Solomon, R. Z., Willett, W. C., Wolk, A., Ziegler, R. G., Smith-Warner, S. A. 2012; 176 (5): 373-386

    Abstract

    Fruit and vegetable intake may protect against pancreatic cancer, since fruits and vegetables are rich in potentially cancer-preventive nutrients. Most case-control studies have found inverse associations between fruit and vegetable intake and pancreatic cancer risk, although bias due to reporting error cannot be ruled out. In most prospective studies, inverse associations have been weaker and imprecise because of small numbers of cases. The authors examined fruit and vegetable intake in relation to pancreatic cancer risk in a pooled analysis of 14 prospective studies from North America, Europe, and Australia (study periods between 1980 and 2005). Relative risks and 2-sided 95% confidence intervals were estimated separately for the 14 studies using the Cox proportional hazards model and were then pooled using a random-effects model. Of 862,584 men and women followed for 7-20 years, 2,212 developed pancreatic cancer. The pooled multivariate relative risks of pancreatic cancer per 100-g/day increase in intake were 1.01 (95% confidence interval (CI): 0.99, 1.03) for total fruits and vegetables, 1.01 (95% CI: 0.99, 1.03) for total fruits, and 1.02 (95% CI: 0.99, 1.06) for total vegetables. Associations were similar for men and women separately and across studies. These results suggest that fruit and vegetable intake during adulthood is not associated with a reduced pancreatic cancer risk.

    View details for DOI 10.1093/aje/kws027

    View details for Web of Science ID 000308226600002

    View details for PubMedID 22875754

  • Age at Last Birth in Relation to Risk of Endometrial Cancer: Pooled Analysis in the Epidemiology of Endometrial Cancer Consortium AMERICAN JOURNAL OF EPIDEMIOLOGY Setiawan, V. W., Pike, M. C., Karageorgi, S., Deming, S. L., Anderson, K., Bernstein, L., Brinton, L. A., Cai, H., Cerhan, J. R., Cozen, W., Chen, C., Doherty, J., Freudenheim, J. L., Goodman, M. T., Hankinson, S. E., Lacey, J. V., Liang, X., Lissowska, J., Lu, L., Lurie, G., Mack, T., Matsuno, R. K., McCann, S., Moysich, K. B., Olson, S. H., Rastogi, R., Rebbeck, T. R., Risch, H., Robien, K., Schairer, C., Shu, X., Spurdle, A. B., Strom, B. L., Thompson, P. J., Ursin, G., Webb, P. M., Weiss, N. S., Wentzensen, N., Xiang, Y., Yang, H. P., Yu, H., Horn-Ross, P. L., De Vivo, I. 2012; 176 (4): 269-278

    Abstract

    Childbearing at an older age has been associated with a lower risk of endometrial cancer, but whether the association is independent of the number of births or other factors remains unclear. Individual-level data from 4 cohort and 13 case-control studies in the Epidemiology of Endometrial Cancer Consortium were pooled. A total of 8,671 cases of endometrial cancer and 16,562 controls were included in the analysis. After adjustment for known risk factors, endometrial cancer risk declined with increasing age at last birth (P(trend) < 0.0001). The pooled odds ratio per 5-year increase in age at last birth was 0.87 (95% confidence interval: 0.85, 0.90). Women who last gave birth at 40 years of age or older had a 44% decreased risk compared with women who had their last birth under the age of 25 years (95% confidence interval: 47, 66). The protective association was similar across the different age-at-diagnosis groups and for the 2 major tumor histologic subtypes (type I and type II). No effect modification was observed by body mass index, parity, or exogenous hormone use. In this large pooled analysis, late age at last birth was independently associated with a reduced risk of endometrial cancer, and the reduced risk persisted for many years.

    View details for DOI 10.1093/aje/kws129

    View details for Web of Science ID 000307500500001

    View details for PubMedID 22831825

  • Variations in sex hormone metabolism genes, postmenopausal hormone therapy and risk of endometrial cancer INTERNATIONAL JOURNAL OF CANCER Razavi, P., Lee, E., Bernstein, L., Van Den Berg, D., Horn-Ross, P. L., Ursin, G. 2012; 130 (7): 1629-1638

    Abstract

    We investigated whether variants in sex steroid hormone metabolism genes modify the effect of hormone therapy (HT) on endometrial cancer risk in postmenopausal non-Hispanic white women. A nested case-control study was conducted within the California Teachers Study (CTS). We genotyped htSNPs in six genes involved in the hormone metabolism in 286 endometrial cancer cases and 488 controls. Odds ratio (OR) and 95% confidence interval (CI) were estimated for each haplotype using unconditional logistic regression, adjusting for age. The strongest interaction was observed between duration of estrogen therapy (ET) use and haplotype 1A in CYP11A1 (p(interaction) = 0.0027; p(interaction) = 0.010 after correcting for multiple testing within each gene). The OR for endometrial cancer per copy of haplotype 1A was 2.00 (95% CI: 1.05-3.96) for long-term ET users and 0.90 (95% CI: 0.69-1.18) for never users. The most significant interaction with estrogen-progestin therapy (EPT) was found for two haplotypes on CYP19A1 and EPT use (haplotype 4A, p(interaction) = 0.024 and haplotype 3B, p(interaction) = 0.043). However, neither this interaction, nor the ET or EPT interactions for any other genes, was statistically significant after correction for multiple testing. Variations in CYP11A1 may modify the effect of ET use on risk of postmenopausal endometrial cancer; however, larger studies are needed to explore these findings further.

    View details for DOI 10.1002/ijc.26163

    View details for Web of Science ID 000299633300017

    View details for PubMedID 21544810

  • The Association Between Neighborhood Characteristics and Body Size and Physical Activity in the California Teachers Study Cohort AMERICAN JOURNAL OF PUBLIC HEALTH Keegan, T. H., Hurley, S., Goldberg, D., Nelson, D. O., Reynolds, P., Bernstein, L., Horn-Ross, P. L., Gomez, S. L. 2012; 102 (4): 689-697

    Abstract

    We considered interactions between physical activity and body mass index (BMI) and neighborhood factors.We used recursive partitioning to identify predictors of low recreational physical activity (< 2.5 hours/week) and overweight and obesity (BMI ? 25.0 kg/m(2)) among 118,315 women in the California Teachers Study. Neighborhood characteristics were based on 2000 US Census data and Reference US business listings.Low physical activity and being overweight or obese were associated with individual sociodemographic characteristics, including race/ethnicity and age. Among White women aged 36 to 75 years, living in neighborhoods with more household crowding was associated with a higher probability of low physical activity (54% vs 45% to 51%). In less crowded neighborhoods where more people worked outside the home, the existence of fewer neighborhood amenities was associated with a higher probability of low physical activity (51% vs 46%). Among non-African American middle-aged women, living in neighborhoods with a lower socioeconomic status was associated with a higher probability of being overweight or obese (46% to 59% vs 38% in high-socioeconomic status neighborhoods).Associations between physical activity, overweight and obesity, and the built environment varied by sociodemographic characteristics in this educated population.

    View details for DOI 10.2105/AJPH.2011.300150

    View details for Web of Science ID 000301870000021

    View details for PubMedID 21852626

  • Carotenoid intakes and risk of breast cancer defined by estrogen receptor and progesterone receptor status: a pooled analysis of 18 prospective cohort studies AMERICAN JOURNAL OF CLINICAL NUTRITION Zhang, X., Spiegelman, D., Baglietto, L., Bernstein, L., Boggs, D. A., van den Brandt, P. A., Buring, J. E., Gapstur, S. M., Giles, G. G., Giovannucci, E., Goodman, G., Hankinson, S. E., Helzlsouer, K. J., Horn-Ross, P. L., Inoue, M., Jung, S., Khudyakov, P., Larsson, S. C., Lof, M., McCullough, M. L., Miller, A. B., Neuhouser, M. L., Palmer, J. R., Park, Y., Robien, K., Rohan, T. E., Ross, J. A., Schouten, L. J., Shikany, J. M., Tsugane, S., Visvanathan, K., Weiderpass, E., Wolk, A., Willett, W. C., Zhang, S. M., Ziegler, R. G., Smith-Warner, S. A. 2012; 95 (3): 713-725

    Abstract

    Epidemiologic studies examining associations between carotenoid intakes and risk of breast cancer by estrogen receptor (ER) and progesterone receptor (PR) status are limited.We investigated these associations in a pooled analysis of 18 cohort studies.Of 1,028,438 participants followed for a maximum follow-up of 26 y across studies, 33,380 incident invasive breast cancers were identified. Study-specific RRs and 95% CIs were estimated by using Cox proportional hazards regression and then pooled by using a random-effects model.?-Carotene, ?-carotene, and lutein/zeaxanthin intakes were inversely associated with the risk of ER-negative (ER-) breast cancer (pooled multivariable RRs of the comparison between the highest and lowest quintiles): ?-carotene (0.87; 95% CI: 0.78, 0.97), ?-carotene (0.84; 95% CI: 0.77, 0.93), and lutein/zeaxanthin (0.87; 95% CI: 0.79, 0.95). These variables were not inversely associated with the risk of ER-positive (ER+) breast cancer (pooled multivariable RRs for the same comparison): ?-carotene (1.04; 95% CI: 0.99, 1.09), ?-carotene (1.04; 95% CI: 0.98, 1.10), and lutein/zeaxanthin (1.00; 95% CI: 0.93, 1.07). Although the pooled RRs for quintile 5 for ?-cryptoxanthin were not significant, inverse trends were observed for ER- and ER+ breast cancer (P-trend ? 0.05). Nonsignificant associations were observed for lycopene intake. The associations were largely not appreciably modified by several breast cancer risk factors. Nonsignificant associations were observed for PR-positive and PR-negative breast cancer.Intakes of ?-carotene, ?-carotene, and lutein/zeaxanthin were inversely associated with risk of ER-, but not ER+, breast cancer. However, the results need to be interpreted with caution because it is unclear whether the observed association is real or due to other constituents in the same food sources.

    View details for DOI 10.3945/ajcn.111.014415

    View details for Web of Science ID 000300638700024

    View details for PubMedID 22277553

  • Body size and the risk of postmenopausal breast cancer subtypes in the California Teachers Study cohort CANCER CAUSES & CONTROL Canchola, A. J., Anton-Culver, H., Bernstein, L., Clarke, C. A., Henderson, K., Ma, H., Ursin, G., Horn-Ross, P. L. 2012; 23 (3): 473-485
  • Coffee, Tea, and Sugar-Sweetened Carbonated Soft Drink Intake and Pancreatic Cancer Risk: A Pooled Analysis of 14 Cohort Studies CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Genkinger, J. M., Li, R., Spiegelman, D., Anderson, K. E., Albanes, D., Bergkvist, L., Bernstein, L., Black, A., van den Brandt, P. A., English, D. R., Freudenheim, J. L., Fuchs, C. S., Giles, G. G., Giovannucci, E., Goldbohm, R. A., Horn-Ross, P. L., Jacobs, E. J., Koushik, A., Mannisto, S., Marshall, J. R., Miller, A. B., Patel, A. V., Robien, K., Rohan, T. E., Schairer, C., Stolzenberg-Solomon, R., Wolk, A., Ziegler, R. G., Smith-Warner, S. A. 2012; 21 (2): 305-318

    Abstract

    Coffee has been hypothesized to have pro- and anticarcinogenic properties, whereas tea may contain anticarcinogenic compounds. Studies assessing coffee intake and pancreatic cancer risk have yielded mixed results, whereas findings for tea intake have mostly been null. Sugar-sweetened carbonated soft drink (SSB) intake has been associated with higher circulating levels of insulin, which may promote carcinogenesis. Few prospective studies have examined SSB intake and pancreatic cancer risk; results have been heterogeneous.In this pooled analysis from 14 prospective cohort studies, 2,185 incident pancreatic cancer cases were identified among 853,894 individuals during follow-up. Multivariate (MV) study-specific relative risks (RR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models and then pooled using a random-effects model.No statistically significant associations were observed between pancreatic cancer risk and intake of coffee (MVRR = 1.10; 95% CI, 0.81-1.48 comparing ?900 to <0 g/d; 237g ? 8oz), tea (MVRR = 0.96; 95% CI, 0.78-1.16 comparing ?400 to 0 g/d; 237g ? 8oz), or SSB (MVRR = 1.19; 95% CI, 0.98-1.46 comparing ?250 to 0 g/d; 355g ? 12oz; P value, test for between-studies heterogeneity > 0.05). These associations were consistent across levels of sex, smoking status, and body mass index. When modeled as a continuous variable, a positive association was evident for SSB (MVRR = 1.06; 95% CI, 1.02-1.12). Conclusion and Impact: Overall, no associations were observed for intakes of coffee or tea during adulthood and pancreatic cancer risk. Although we were only able to examine modest intake of SSB, there was a suggestive, modest positive association for risk of pancreatic cancer for intakes of SSB.

    View details for DOI 10.1158/1055-9965.EPI-11-0945-T

    View details for Web of Science ID 000300073300009

    View details for PubMedID 22194529

  • Body size and the risk of postmenopausal breast cancer subtypes in the California Teachers Study cohort. Cancer causes & control : CCC Canchola, A. J., Anton-Culver, H., Bernstein, L., Clarke, C. A., Henderson, K., Ma, H., Ursin, G., Horn-Ross, P. L. 2012

    Abstract

    PURPOSE: To evaluate how the association between body size and breast cancer risk varies by tumor receptor subtype, host factors, and other exposures among women in the California Teachers Study cohort. METHODS: Among 52,642 postmenopausal women, 2,321 developed invasive breast cancer with known estrogen- and progesterone-receptor status (1,652 ER+PR+, 338 ER+PR-, and 312 ER-PR-) between 1995 and 2007. In a subset of 35,529 with waist circumference data, 1,377 developed invasive breast cancer with known ERPR status (991 ER+PR+, 208 ER+PR-, 169 ER-PR-) between 1997 and 2007. Multivariate Cox regression was performed to estimate relative risks (RR) and 95% confidence intervals (CI). RESULTS: Obesity, adult weight gain of ?40 pounds, greater abdominal adiposity, and greater height increased the risk of ER+PR+ breast cancer. The increased risk associated with postmenopausal obesity was limited to those who did not use hormone therapy (HT) at cohort entry (RR = 1.37; 95% CI, 1.05-1.78 for BMI ? 30 vs. < 25 kg/m(2); p-interaction = 0.14) and those who were not overweight or obese at age 18 (p-interaction = 0.06). The increased risk associated with greater abdominal adiposity was limited to those who were not also overweight or obese (p-interaction = 0.01). Neither obesity, abdominal adiposity, nor height was associated with the risk of ER-PR- tumors. CONCLUSIONS: The effects of body size on postmenopausal breast cancer risk differed by hormone receptor subtype, and among women with ER+PR+ tumors, by HT use and early adult body size.

    View details for PubMedID 22286371

  • Nativity and papillary thyroid cancer incidence rates among Hispanic women in California CANCER Horn-Ross, P. L., Chang, E. T., Clarke, C. A., Keegan, T. H., Rull, R. P., Thu Quach, T., Gomez, S. L. 2012; 118 (1): 216-222

    Abstract

    Overall, the incidence of papillary thyroid cancer in Hispanic women residing in the United States (US) is similar to that of non-Hispanic white women. However, little is known as to whether rates in Hispanic women vary by nativity, which may influence exposure to important risk factors.Nativity-specific incidence rates among Hispanic women were calculated for papillary thyroid cancer using data from the California Cancer Registry (CCR) for the period 1988-2004. For the 35% of cases for whom birthplace information was not available from the CCR, nativity was statistically imputed based on age at Social Security number issuance. Population estimates were extracted based on US Census data. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were also estimated.In young (age <55 years) Hispanic women, the incidence of papillary thyroid cancer among US-born women (10.65 per 100,000) was significantly greater than that for foreign-born women (6.67 per 100,000; IRR, 1.60 [95% CI, 1.44-1.77]). The opposite pattern was observed in older women. The age-specific patterns showed marked differences by nativity: among foreign-born women, rates increased slowly until age 70 years, whereas among US-born women, incidence rates peaked during the reproductive years. Incidence rates increased over the study period in all subgroups.Incidence rates of papillary thyroid cancer vary by nativity and age among Hispanic women residing in California. These patterns can provide insight for future etiologic investigations of modifiable risk factors for this increasingly common and understudied cancer.

    View details for DOI 10.1002/cncr.26223

    View details for Web of Science ID 000298549700027

    View details for PubMedID 21692062

  • Early-Life Factors and Breast Cancer Risk in Hispanic Women: the Role of Adolescent Body Size CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Sangaramoorthy, M., Phipps, A. I., Horn-Ross, P. L., Koo, J., John, E. M. 2011; 20 (12): 2572-2582

    Abstract

    Adult body size has long been known to influence breast cancer risk, and there is now increasing evidence that childhood and adolescent body size may also play a role.We assessed the association with body size at ages 10, 15, and 20 years in 475 premenopausal and 775 postmenopausal Hispanic women who participated in a population-based case-control study of breast cancer conducted from 1995 to 2004 in the San Francisco Bay Area. We used unconditional logistic regression to estimate ORs and 95% CIs for the associations with self-reported relative weight compared with peers and body build at ages 10, 15, and 20 years.In premenopausal women, we found inverse associations with relative weight compared with peers, with ORs of 0.63 (P(trend) = 0.05), 0.31 (P(trend) < 0.01), and 0.44 (P(trend) = 0.02) for heavier versus lighter weight at ages 10, 15, and 20 years, respectively. These inverse associations were stronger in currently overweight women and U.S.-born women and did not differ significantly for case groups defined by estrogen receptor status. In postmenopausal women, not currently using hormone therapy, inverse associations with relative weight were limited to U.S.-born Hispanics.Large body size at a young age may have a long-lasting influence on breast cancer risk in premenopausal, and possibly postmenopausal, Hispanic women that is independent of current body mass index.These findings need to be weighed against adverse health effects associated with early-life obesity.

    View details for DOI 10.1158/1055-9965.EPI-11-0848

    View details for Web of Science ID 000298234900013

    View details for PubMedID 22056503

  • Folate Intake and Risk of Pancreatic Cancer: Pooled Analysis of Prospective Cohort Studies JOURNAL OF THE NATIONAL CANCER INSTITUTE Bao, Y., Michaud, D. S., Spiegelman, D., Albanes, D., Anderson, K. E., Bernstein, L., van den Brandt, P. A., English, D. R., Freudenheim, J. L., Fuchs, C. S., Giles, G. G., Giovannucci, E., Goldbohm, R. A., Hakansson, N., Horn-Ross, P. L., Jacobs, E. J., Kitahara, C. M., Marshall, J. R., Miller, A. B., Robien, K., Rohan, T. E., Schatzkin, A., Stevens, V. L., Stolzenberg-Solomon, R. Z., Virtamo, J., Wolk, A., Ziegler, R. G., Smith-Warner, S. A. 2011; 103 (24): 1840-1850

    Abstract

    Epidemiological studies evaluating the association between folate intake and risk of pancreatic cancer have produced inconsistent results. The statistical power to examine this association has been limited in previous studies partly because of small sample size and limited range of folate intake in some studies.We analyzed primary data from 14 prospective cohort studies that included 319,716 men and 542,948 women to assess the association between folate intake and risk of pancreatic cancer. Folate intake was assessed through a validated food-frequency questionnaire at baseline in each study. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random effects model. All statistical tests were two-sided.During 7-20 years of follow-up across studies, 2195 pancreatic cancers were identified. No association was observed between folate intake and risk of pancreatic cancer in men and women (highest vs lowest quintile: dietary folate intake, pooled multivariable RR = 1.06, 95% CI = 0.90 to 1.25, P(trend) = .47; total folate intake [dietary folate and supplemental folic acid], pooled multivariable RR = 0.96, 95% CI = 0.80 to 1.16, P(trend) = .90). No between-study heterogeneity was observed (for dietary folate, P(heterogeneity) = .15; for total folate, P(heterogeneity) = .22).Folate intake was not associated with overall risk of pancreatic cancer in this large pooled analysis.

    View details for DOI 10.1093/jnci/djr431

    View details for Web of Science ID 000298391000009

    View details for PubMedID 22034634

  • A pooled analysis of 14 cohort studies of anthropometric factors and pancreatic cancer risk INTERNATIONAL JOURNAL OF CANCER Genkinger, J. M., Spiegelman, D., Anderson, K. E., Bernstein, L., van den Brandt, P. A., Calle, E. E., English, D. R., Folsom, A. R., Freudenheim, J. L., Fuchs, C. S., Giles, G. G., Giovannucci, E., Horn-Ross, P. L., Larsson, S. C., Leitzmann, M., Mannisto, S., Marshall, J. R., Miller, A. B., Patel, A. V., Rohan, T. E., Stolzenberg-Solomon, R. Z., Verhage, B. A., Virtamo, J., Willcox, B. J., Wolk, A., Ziegler, R. G., Smith-Warner, S. A. 2011; 129 (7): 1708-1717

    Abstract

    Epidemiologic studies of pancreatic cancer risk have reported null or nonsignificant positive associations for obesity, while associations for height have been null. Waist and hip circumference have been evaluated infrequently. A pooled analysis of 14 cohort studies on 846,340 individuals was conducted; 2,135 individuals were diagnosed with pancreatic cancer during follow-up. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were calculated by Cox proportional hazards models, and then pooled using a random effects model. Compared to individuals with a body mass index (BMI) at baseline between 21-22.9 kg/m(2) , pancreatic cancer risk was 47% higher (95%CI:23-75%) among obese (BMI ? 30 kg/m(2) ) individuals. A positive association was observed for BMI in early adulthood (pooled multivariate [MV]RR = 1.30, 95%CI = 1.09-1.56 comparing BMI ? 25 kg/m(2) to a BMI between 21 and 22.9 kg/m(2) ). Compared to individuals who were not overweight in early adulthood (BMI < 25 kg/m(2) ) and not obese at baseline (BMI < 30 kg/m(2) ), pancreatic cancer risk was 54% higher (95%CI = 24-93%) for those who were overweight in early adulthood and obese at baseline. We observed a 40% higher risk among individuals who had gained BMI ? 10 kg/m(2) between BMI at baseline and younger ages compared to individuals whose BMI remained stable. Results were either similar or slightly stronger among never smokers. A positive association was observed between waist to hip ratio (WHR) and pancreatic cancer risk (pooled MVRR = 1.35 comparing the highest versus lowest quartile, 95%CI = 1.03-1.78). BMI and WHR were positively associated with pancreatic cancer risk. Maintaining normal body weight may offer a feasible approach to reducing morbidity and mortality from pancreatic cancer.

    View details for DOI 10.1002/ijc.25794

    View details for Web of Science ID 000293246600017

    View details for PubMedID 21105029

  • Adulthood residential ultraviolet radiation, sun sensitivity, dietary vitamin D, and risk of lymphoid malignancies in the California Teachers Study BLOOD Chang, E. T., Canchola, A. J., Cockburn, M., Lu, Y., Wang, S. S., Bernstein, L., Clarke, C. A., Horn-Ross, P. L. 2011; 118 (6): 1591-1599

    Abstract

    To lend clarity to inconsistent prior findings of an inverse association between ultraviolet radiation (UVR) exposure and risk of lymphoid malignancies, we examined the association of prospectively ascertained residential ambient UVR exposure with risk of non-Hodgkin lymphomas (NHLs), multiple myeloma (MM), and classical Hodgkin lymphoma in the California Teachers Study cohort. Among 121 216 eligible women, 629 were diagnosed with NHL, 119 with MM, and 38 with Hodgkin lymphoma between 1995-1996 and 2007. Cox proportional hazards regression was used to estimate incidence rate ratios (RRs) with 95% confidence intervals (CIs). Residential UVR levels within a 20-km radius were associated with reduced risk of overall NHL (RR for highest vs lowest statewide quartile of minimum UVR [? 5100 vs < 4915 W-h/m(2)], 0.58; 95% CI, 0.42-0.80), especially diffuse large B-cell lymphoma (RR, 0.36; 95% CI, 0.17-0.78) and chronic lymphocytic leukemia/small lymphocytic lymphoma (RR, 0.46; 95% CI, 0.21-1.01), and MM (RR for maximum UVR, 0.57; 95% CI, 0.36-0.90). These associations were not modified by skin sensitivity to sunlight, race/ethnicity, body mass index, or neighborhood socioeconomic status. Dietary vitamin D also was not associated with risk of lymphoid malignancies. These results support a protective effect of routine residential UVR exposure against lymphomagenesis through mechanisms possibly independent of vitamin D.

    View details for DOI 10.1182/blood-2011-02-336065

    View details for Web of Science ID 000293787300026

    View details for PubMedID 21622649

  • Hormonal Factors and the Risk of Papillary Thyroid Cancer in the California Teachers Study Cohort CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Horn-Ross, P. L., Canchola, A. J., Ma, H., Reynolds, P., Bernstein, L. 2011; 20 (8): 1751-1759

    Abstract

    Despite the increasing incidence of thyroid cancer, there is limited information on its etiology. The strikingly higher rates in young women, compared with men, suggest that sex steroid hormones may be involved in the development of this disease.We investigated the effects of menstrual, reproductive, and other hormonal factors on papillary thyroid cancer risk in the prospective California Teachers Study cohort. Among 117,646 women, 233 were diagnosed with invasive histologically confirmed papillary thyroid cancer after cohort enrollment and before January 1, 2008. Relative risks (RR) and 95% CIs were estimated by using Cox proportional hazards regression models.Among younger women (age <45 years at baseline; approximately one-third of the cohort), but not older women, later age at menarche (age ?14 years) was associated with increased risk (RR = 1.88, 95% CI: 1.13-3.13; p(interaction) by age = 0.06). Risk was also increased among young women who had longer (>30 days) adolescent menstrual cycles (RR = 1.78, 95% CI: 1.01-3.14) and whose last pregnancy had ended within five years of cohort enrollment (RR = 2.21, 95% CI: 1.13-4.34). Among older women (age ?45 years at baseline), ever use of estrogen-only therapy was associated with a statistically nonsignificant increase in risk (RR = 1.69, 95% CI: 0.95-2.98).The findings from this prospective analysis suggest that several factors related to delayed pubertal development and the transient effects of pregnancy may be particularly important in influencing risk in young women.These results suggest the importance of future research into the role of progesterone and the estrogen-to-progesterone ratio.

    View details for DOI 10.1158/1055-9965.EPI-11-0381

    View details for Web of Science ID 000293625600021

    View details for PubMedID 21791618

  • Papillary thyroid cancer incidence rates vary significantly by birthplace in Asian American women CANCER CAUSES & CONTROL Horn-Ross, P. L., McClure, L. A., Chang, E. T., Clarke, C. A., Keegan, T. H., Rull, R. P., Quach, T., Gomez, S. L. 2011; 22 (3): 479-485

    Abstract

    To investigate how birthplace influences the incidence of papillary thyroid cancer among Asian American women.Birthplace- and ethnic-specific age-adjusted and age-specific incidence rates were calculated using data from the California Cancer Registry for the period 1988-2004. Birthplace was statistically imputed for 30% of cases using a validated imputation method based on age at Social Security number issuance. Population estimates were obtained from the US Census. Incidence rate ratios (IRR) and 95% confidence intervals (CI) were estimated for foreign-born vs. US-born women.Age-adjusted incidence rates of papillary thyroid cancer among Filipina (13.7 per 100,000) and Vietnamese (12.7) women were more than double those of Japanese women (6.2). US-born Chinese (IRR = 0.48, 95% CI: 0.40-0.59) and Filipina women (IRR = 0.74, 95% CI: 0.58-0.96) had significantly higher rates than those who were foreign-born; the opposite was observed for Japanese women (IRR = 1.55, 95% CI: 1.17-2.08). The age-specific patterns among all foreign-born Asian women and US-born Japanese women showed a slow steady increase in incidence until age 70. However, among US-born Asian women (except Japanese), substantially elevated incidence rates during the reproductive and menopausal years were evident.Ethnic- and birthplace-variation in papillary thyroid cancer incidence can provide insight into the etiology of this increasingly common and understudied cancer.

    View details for DOI 10.1007/s10552-010-9720-5

    View details for Web of Science ID 000288542400015

    View details for PubMedID 21207130

  • Age-specific effects of hormone therapy use on overall mortality and ischemic heart disease mortality among women in the California Teachers Study MENOPAUSE-THE JOURNAL OF THE NORTH AMERICAN MENOPAUSE SOCIETY Stram, D. O., Liu, Y., Henderson, K. D., Sullivan-Halley, J., Luo, J., Saxena, T., Reynolds, P., Chang, E. T., Neuhausen, S. L., Horn-Ross, P. L., Bernstein, L., Ursin, G. 2011; 18 (3): 253-261

    Abstract

    Although the Women's Health Initiative trial suggested that menopausal hormone therapy (HT) does not reduce coronary heart disease mortality overall, subsequent results have suggested that there may be a benefit in younger women. The California Teachers Study questionnaire and mortality data were used to examine whether age modified the association between HT and the relative risk of overall mortality and ischemic heart disease deaths.Participants from the California Teachers Study were 71,237 postmenopausal women (mean age, 63 y; range, 36-94 y) followed prospectively for mortality and other outcomes from 1995-1996 through 2004.Age at baseline was a much more important modifier of HT effects than was age at start of therapy. Risks for all-cause mortality (n = 8,399) were lower for younger current HT users at baseline than for never users (for women ? 0 y: hazard ratio, 0.54; 95% CI, 0.46-0.62). These risk reductions greatly diminished, in a roughly linear fashion, with increasing baseline age (for women 85-94 y: hazard ratio, 0.94; 95% CI, 0.81-1.10 for all-cause mortality). Similar results were seen for ischemic heart disease deaths (n = 1,464). No additional significant modifying effects of age at first use, duration of use, or formulation were apparent.These results provide evidence that reduced risks of mortality associated with HT use are observed among younger users but not for older postmenopausal women, even those starting therapy close to their time of menopause.

    View details for DOI 10.1097/gme.0b013e3181f0839a

    View details for Web of Science ID 000287658600006

    View details for PubMedID 20881652

  • Dietary phytocompounds and risk of lymphoid malignancies in the California Teachers Study cohort CANCER CAUSES & CONTROL Chang, E. T., Canchola, A. J., Clarke, C. A., Lu, Y., West, D. W., Bernstein, L., Wang, S. S., Horn-Ross, P. L. 2011; 22 (2): 237-249

    Abstract

    We examined whether dietary intake of isoflavones, lignans, isothiocyanates, antioxidants, or specific foods rich in these compounds is associated with reduced risk of B-cell non-Hodgkin lymphoma (NHL), multiple myeloma (MM), or Hodgkin lymphoma (HL) in a large, prospective cohort of women.Between 1995-1996 and 31 December 2007, among 110,215 eligible members of the California Teachers Study cohort, 536 women developed incident B-cell NHL, 104 developed MM, and 34 developed HL. Cox proportional hazards regression, with age as the time scale, was used to estimate adjusted rate ratios (RRs) with 95% confidence intervals (CIs) for risk of lymphoid malignancies.Weak inverse associations with risk of diffuse large B-cell lymphoma were observed for isothiocyanates (RR for ?12.1 vs. <2.7 mcM/day = 0.67, 95% CI: 0.43-1.05) and an antioxidant index measuring hydroxyl radical absorbance capacity (RR for ?2.2 vs. <0.9 ?M Trolox equiv/g/day = 0.68, 95% CI: 0.42-1.10; p (trend) = 0.08). Risk of other NHL subtypes, overall B-cell NHL, MM, or HL was not generally associated with dietary intake of isoflavones, lignans, isothiocyanates, antioxidants, or major food sources of these compounds.Isoflavones, lignans, isothiocyanates, and antioxidant compounds are not associated with risk of most B-cell malignancies, but some phytocompounds may decrease the risk of selected subtypes.

    View details for DOI 10.1007/s10552-010-9692-5

    View details for Web of Science ID 000286465000009

    View details for PubMedID 21107674

  • Adult Body Size, Hormone Receptor Status, and Premenopausal Breast Cancer Risk in a Multiethnic Population The San Francisco Bay Area Breast Cancer Study AMERICAN JOURNAL OF EPIDEMIOLOGY John, E. M., Sangaramoorthy, M., Phipps, A. I., Koo, J., Horn-Ross, P. L. 2011; 173 (2): 201-216

    Abstract

    Large body size has been associated with a reduced risk of premenopausal breast cancer in non-Hispanic white women. Data on other racial/ethnic populations are limited. The authors examined the association between premenopausal breast cancer risk and adult body size in 672 cases and 808 controls aged ?35 years from a population-based case-control study conducted in 1995-2004 in the San Francisco Bay Area (Hispanics: 375 cases, 483 controls; African Americans: 154 cases, 160 controls; non-Hispanic whites: 143 cases, 165 controls). Multivariate adjusted odds ratios and 95% confidence intervals were calculated using unconditional logistic regression. Height was associated with increased breast cancer risk (highest vs. lowest quartile: odds ratio = 1.77, 95% confidence interval: 1.23, 2.53; P(trend) < 0.01); the association did not vary by hormone receptor status or race/ethnicity. Body mass index (measured as weight (kg) divided by height (m) squared) was inversely associated with risk in all 3 racial/ethnic groups, but only for estrogen receptor- and progesterone receptor-positive tumors (body mass index ?30 vs. <25: odds ratio = 0.42; 95% confidence interval: 0.29, 0.61). Other body size measures (current weight, body build, adult weight gain, young adult weight and body mass index, waist circumference, and waist-to-height ratio) were similarly inversely associated with risk of estrogen receptor- and progesterone receptor-positive breast cancer but not estrogen receptor- and progesterone receptor-negative disease. Despite racial/ethnic differences in body size, inverse associations were similar across the 3 racial/ethnic groups when stratified by hormone receptor status.

    View details for DOI 10.1093/aje/kwq345

    View details for Web of Science ID 000285627500010

    View details for PubMedID 21084558

  • The association of polymorphisms in hormone metabolism pathway genes, menopausal hormone therapy, and breast cancer risk: a nested case-control study in the California Teachers Study cohort BREAST CANCER RESEARCH Lee, E., Schumacher, F., Lewinger, J. P., Neuhausen, S. L., Anton-Culver, H., Horn-Ross, P. L., Henderson, K. D., Ziogas, A., Van Den Berg, D., Bernstein, L., Ursin, G. 2011; 13 (2)

    Abstract

    The female sex steroids estrogen and progesterone are important in breast cancer etiology. It therefore seems plausible that variation in genes involved in metabolism of these hormones may affect breast cancer risk, and that these associations may vary depending on menopausal status and use of hormone therapy.We conducted a nested case-control study of breast cancer in the California Teachers Study cohort. We analyzed 317 tagging single nucleotide polymorphisms (SNPs) in 24 hormone pathway genes in 2746 non-Hispanic white women: 1351 cases and 1395 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by fitting conditional logistic regression models using all women or subgroups of women defined by menopausal status and hormone therapy use. P values were adjusted for multiple correlated tests (PACT).The strongest associations were observed for SNPs in SLCO1B1, a solute carrier organic anion transporter gene, which transports estradiol-17?-glucuronide and estrone-3-sulfate from the blood into hepatocytes. Ten of 38 tagging SNPs of SLCO1B1 showed significant associations with postmenopausal breast cancer risk; 5 SNPs (rs11045777, rs11045773, rs16923519, rs4149057, rs11045884) remained statistically significant after adjusting for multiple testing within this gene (PACT = 0.019-0.046). In postmenopausal women who were using combined estrogen-progestin therapy (EPT) at cohort enrollment, the OR of breast cancer was 2.31 (95% CI = 1.47-3.62) per minor allele of rs4149013 in SLCO1B1 (P = 0.0003; within-gene PACT = 0.002; overall PACT = 0.023). SNPs in other hormone pathway genes evaluated in this study were not associated with breast cancer risk in premenopausal or postmenopausal women.We found evidence that genetic variation in SLCO1B1 is associated with breast cancer risk in postmenopausal women, particularly among those using EPT.

    View details for DOI 10.1186/bcr2859

    View details for Web of Science ID 000292694600026

    View details for PubMedID 21457551

  • Alcohol Consumption Over Time and Risk of Lymphoid Malignancies in the California Teachers Study Cohort AMERICAN JOURNAL OF EPIDEMIOLOGY Chang, E. T., Clarke, C. A., Canchola, A. J., Lu, Y., Wang, S. S., Ursin, G., West, D. W., Bernstein, L., Horn-Ross, P. L. 2010; 172 (12): 1373-1383

    Abstract

    Several previous studies found inverse associations between alcohol consumption and risk of non-Hodgkin lymphoma (NHL) and multiple myeloma. However, most studies were retrospective, and few distinguished former drinkers or infrequent drinkers from consistent nondrinkers. Therefore, the authors investigated whether history of alcohol drinking affected risks of NHL and multiple myeloma among 102,721 eligible women in the California Teachers Study, a prospective cohort study in which 496 women were diagnosed with B-cell NHL and 101 were diagnosed with multiple myeloma between 1995-1996 and December 31, 2007. Incidence rate ratios and 95% confidence intervals were estimated using Cox proportional hazards regression. Risk of all types of B-cell NHL combined or multiple myeloma was not associated with self-reported past consumption of alcohol, beer, wine, or liquor at ages 18-22 years, at ages 30-35 years, or during the year before baseline. NHL subtypes were inconsistently associated with alcohol intake. However, women who were former alcohol drinkers at baseline were at elevated risk of overall B-cell NHL (rate ratio = 1.46, 95% confidence interval: 1.08, 1.97) and follicular lymphoma (rate ratio = 1.81, 95% confidence interval: 1.00, 3.28). The higher risk among former drinkers emphasizes the importance of classifying both current and past alcohol consumption and suggests that factors related to quitting drinking, rather than alcohol itself, may increase B-cell NHL risk.

    View details for DOI 10.1093/aje/kwq309

    View details for Web of Science ID 000285193200008

    View details for PubMedID 20952595

  • Body size and the risk of ovarian cancer by hormone therapy use in the California Teachers Study cohort CANCER CAUSES & CONTROL Canchola, A. J., Chang, E. T., Bernstein, L., Largent, J. A., Reynolds, P., Deapen, D., Henderson, K. D., Ursin, G., Horn-Ross, P. L. 2010; 21 (12): 2241-2248

    Abstract

    To investigate whether obesity and hormone therapy (HT) are associated with ovarian cancer risk among women in the California Teachers Study cohort.Of 56,091 women age ? 45 years, 277 developed epithelial ovarian cancer between 1995 and 2007. Multivariate Cox regression was performed.Among women who never used HT, greater adult weight gain, waist circumference and waist-to-height ratio, but not adult BMI, increased risk of ovarian cancer. Compared to women who never used HT and had a stable adult weight, risk of ovarian cancer was increased in women who gained ? 40 lb (relative risk (RR) 1.8, 95% confidence interval (CI): 1.0-3.0) or used HT for >5 years (RR 2.3 95% CI: 1.3-4.1). Having both exposures (RR 1.9, 95% CI: 0.99-3.5), however, did not increase risk more than having either alone. Results were similar for waist circumference and weight-to-height ratio; however, differences across HT groups were not statistically significant.This study suggests that abdominal adiposity and weight gain, but not overall obesity, increase ovarian cancer risk and that there may be a threshold level beyond which additional hormones, whether exogenous or endogenous, do not result in additional elevation in risk. However, large pooled analyses are needed to confirm these findings.

    View details for DOI 10.1007/s10552-010-9647-x

    View details for Web of Science ID 000288609600032

    View details for PubMedID 20924664

  • Hypertension, antihypertensive medication use, and breast cancer risk in the California Teachers Study cohort CANCER CAUSES & CONTROL Largent, J. A., Bernstein, L., Horn-Ross, P. L., Marshall, S. F., Neuhausen, S., Reynolds, P., Ursin, G., Zell, J. A., Ziogas, A., Anton-Culver, H. 2010; 21 (10): 1615-1624

    Abstract

    We investigated the association between hypertension, antihypertensive (AH) medication use, and breast cancer in a large prospective study, the California Teachers Study (CTS).Information on history of hypertension and lifetime regular use of AH medications was collected from 114,549 women in 1995-1996. Among them, 4,151 invasive breast cancers were diagnosed between 1995 and 2006. Additional information on AH use was collected from 73,742 women in 2000-2001, and 1,714 of these women were subsequently diagnosed with breast cancer. Cox proportional hazards regression was used to estimate relative risks (RR) and 95% confidence intervals (CI) for breast cancer.Use of AH medication for ?5 years, when compared with no use, was associated with a modest increased risk of invasive breast cancer (RR = 1.18, 95%CI 1.02-1.36). This increased risk appeared to be confined to estrogen receptor (ER)-positive tumors (RR = 1.21, 95%CI 1.03-1.43) and pre-/peri-menopausal women (RR = 1.58, 95%CI 1.11-2.25).Increased risk of invasive breast cancer was observed for long-term (?5 years) AH use, and this appeared to be confined to ER + breast cancer and younger women.

    View details for DOI 10.1007/s10552-010-9590-x

    View details for Web of Science ID 000281934800009

    View details for PubMedID 20526803

  • Body size and the risk of endometrial cancer by hormone therapy use in postmenopausal women in the California Teachers Study cohort CANCER CAUSES & CONTROL Canchola, A. J., Chang, E. T., Bernstein, L., Largent, J. A., Reynolds, P., Deapen, D., Ursin, G., Horn-Ross, P. L. 2010; 21 (9): 1407-1416

    Abstract

    To investigate whether hormone therapy (HT) and obesity are associated with endometrial cancer risk among postmenopausal women in the California Teachers Study cohort.Of 28,418 postmenopausal women, 395 developed type 1 endometrial cancer between 1995 and 2006. Multivariate Cox regression was performed to estimate relative risks (RR), stratified by HT use (never used, ever estrogen alone (ET) or exclusively estrogen-plus-progestin (EPT)).Among women who never used HT, overall and abdominal adiposity were associated with increased risk; when evaluated simultaneously, abdominal adiposity was more strongly associated (RR 2.2, 95% confidence interval (CI): 1.1-4.5 for waist >or=35 vs. <35 inches). Among women who ever used ET, risk was increased in women with BMI >or= 25 kg/m(2) (RR 1.6, 95% CI: 1.1-2.3 vs. <25 kg/m(2)). Neither overall nor abdominal obesity was associated with risk in women who exclusively used EPT (p-interaction <0.001 for BMI by HT use).Among women who never used HT, risk was strongly positively related to obesity and may have been influenced more by abdominal than by overall adiposity; however, due to small numbers, this latter finding requires replication. Among women who ever used ET, being overweight at baseline predicted higher risk, whereas use of EPT mitigated any effects of obesity.

    View details for DOI 10.1007/s10552-010-9568-8

    View details for Web of Science ID 000280902000006

    View details for PubMedID 20431936

  • Genetic variation in the progesterone receptor gene and risk of endometrial cancer: a haplotype-based approach CARCINOGENESIS Lee, E., Hsu, C., Haiman, C. A., Razavi, P., Horn-Ross, P. L., Van Den Berg, D., Bernstein, L., Le Marchand, L., Henderson, B. E., Setiawan, V. W., Ursin, G. 2010; 31 (8): 1392-1399

    Abstract

    It is well established that estrogen increases endometrial cancer risk, whereas progesterone opposes the estrogen effects. The PROGINS allele of the progesterone receptor (PGR) gene reduces the function of PGR and has been associated with increased risk of the endometrioid type ovarian cancer. We investigated whether genetic variation in PGR is also associated with endometrial cancer risk using a haplotype-based approach.We pooled data from two endometrial cancer case-control studies that were nested within two prospective cohorts, the Multiethnic Cohort Study and the California Teachers Study. Seventeen haplotype-tagging single nucleotide polymorphisms (SNPs) across four linkage disequilibrium (LD) blocks spanning the PGR locus were genotyped in 583 incident cases and 1936 control women. Odds ratios (ORs) and 95% confidence intervals (CIs) associated with each haplotype were estimated using conditional logistic regression, stratified by age and ethnicity.Genetic variation in LD block 3 of the PGR locus was associated with endometrial cancer risk (P(global test) = 0.002), with haplotypes 3C, 3D and 3F associated with 31-34% increased risk. Among whites (383 cases/840 controls), genetic variation in all four blocks was associated with increased endometrial cancer risk (P(global test) = 0.010, 0.013, 0.005 and 0.020). Haplotypes containing the PROGINS allele and several haplotypes in blocks 1, 3 and 4 were associated with 34-77% increased risk among whites. SNP analyses for whites suggested that rs608995, partially linked to the PROGINS allele (r(2) = 0.6), was associated with increased risk (OR = 1.30, 95% CI = 1.06-1.59).Our results suggest that genetic variation in the PGR region is associated with endometrial cancer risk.

    View details for DOI 10.1093/carcin/bgq113

    View details for Web of Science ID 000280703800012

    View details for PubMedID 20547493

  • Lifetime Physical Activity and Risk of Endometrial Cancer CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION John, E. M., Koo, J., Horn-Ross, P. L. 2010; 19 (5): 1276-1283

    Abstract

    The role of moderate physical activity and life patterns of activity in reducing endometrial cancer risk remains uncertain.We assessed lifetime histories of activity from recreation, transportation, chores, and occupation and other risk factors in a population-based case-control study of endometrial cancer conducted in the San Francisco Bay area. The analysis was based on 472 newly diagnosed cases ascertained by the regional cancer registry and 443 controls identified by random-digit dialing who completed an in-person interview.Reduced risks associated with greater lifetime physical activity (highest versus lowest tertile) were found for both total activity [odds ratio (OR), 0.61; 95% confidence interval (95% CI), 0.43-0.87; Ptrend=0.01] and activity of moderate intensity (OR, 0.44; 95% CI, 0.30-0.64; Ptrend<0.0001). Compared with women with low lifetime physical activity (below median), those with greater activity throughout life had a higher reduction in risk (OR, 0.62; 95% CI, 0.44-0.88). Inverse associations were stronger in obese and overweight women, but differences were not statistically significantly different from those in normal-weight women.These findings suggest that physical activity in adulthood, even of moderate intensity, may be effective in lowering the risk of endometrial cancer, particularly among those at highest risk for this disease.The results emphasize the importance of evaluating lifetime histories of physical activity from multiple sources, including both recreational and nonrecreational activities of various intensities, to fully understand the relation between physical activity and disease risk.

    View details for DOI 10.1158/1055-9965.EPI-09-1316

    View details for Web of Science ID 000278489800015

    View details for PubMedID 20406960

  • Anthropometric Characteristics and Multiple Myeloma Risk EPIDEMIOLOGY Lu, Y., Sullivan-Halley, J., Henderson, K. D., Ma, H., Horn-Ross, P. L., Reynolds, P., Cress, R., Bernstein, L. 2010; 21 (2): 272-273

    View details for DOI 10.1097/EDE.0b013e3181cc9241

    View details for Web of Science ID 000275426000020

    View details for PubMedID 20160567

  • Long-term Postmenopausal Hormone Therapy and Endometrial Cancer CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Razavi, P., Pike, M. C., Horn-Ross, P. L., Templeman, C., Bernstein, L., Ursin, G. 2010; 19 (2): 475-483

    Abstract

    Estrogen-alone therapy (ET) or estrogen and progestin (EPT) as menopausal hormone therapy (HT) has been commonly used to alleviate menopausal symptoms. Treatments containing > or = 10 days per month of progestin are considered relatively safe with respect to endometrial cancer risk. However, the endometrial safety of long-term EPT regimens is uncertain. We conducted a case-control study of 311 invasive endometrial cancer cases and 570 controls nested within the California Teachers Study cohort. We used unconditional logistic regression to obtain odds ratios (OR) and 95% confidence intervals (95% CI) for the association between long-term HT use and endometrial cancer risk, and to assess the modifying effect of body mass index (BMI). Long-term (> or = 10 years) use of ET, sequential EPT with <10 days per month progestin, and continuous-combined EPT (> or = 25 days/month progestin) were all associated with an elevated risk of endometrial cancer (OR, 4.5; 95% CI, 2.5-8.1; OR, 4.4; 95% CI, 1.7-11.2; and OR, 2.1; 95% CI, 1.3-3.3, respectively; all P(trend) < 0.001). The risk associated with short-term use was elevated only for ET preparations. The association for continuous-combined EPT was confined to thinner women (BMI, <25 kg/m2; P(interaction) = 0.03). Among heavier women (BMI, > or = 25 kg/m2), use of continuous-combined EPT was associated with a statistically nonsignificant reduction in risk. These findings confirm that long-term use of ET, sequential EPT, or, among normal weight women, continuous-combined EPT is associated with increased risk of endometrial cancer.

    View details for DOI 10.1158/1055-9965.EPI-09-0712

    View details for Web of Science ID 000278403900021

    View details for PubMedID 20086105

  • Recent breast cancer incidence trends according to hormone therapy use: the California Teachers Study cohort BREAST CANCER RESEARCH Marshall, S. F., Clarke, C. A., Deapen, D., Henderson, K., Largent, J., Neuhausen, S. L., Reynolds, P., Ursin, G., Horn-Ross, P. L., Stram, D. O., Templeman, C., Bernstein, L. 2010; 12 (1)

    Abstract

    Recent, international declines in breast cancer incidence are unprecedented, and the causes remain controversial. Few data sources can address breast cancer incidence trends according to pertinent characteristics like hormone therapy use history.We used the prospective California Teachers Study to evaluate changes in self-reported use of menopausal hormone therapy (HT) between 1995 to 1996 and 2005 to 2006 and age-adjusted breast cancer incidence among 74,647 participants aged 50 years or older. Breast cancer occurrence was determined by linkage with the California Cancer Registry.During 517,286 woman years of follow up, 565 in situ and 2,668 invasive breast cancers were diagnosed. In situ breast cancer incidence rates in this population did not change significantly from 2000 to 2002 to 2003 to 2005, whereas rates of invasive breast cancer declined significantly by 26.0% from 528.0 (95% confidence intervals (CI) = 491.1, 564.9) per 100,000 women in 2000 to 2002 to 390.6 (95% CI = 355.6, 425.7) in 2003 to 2005. The decline in invasive breast cancer incidence rates was restricted to estrogen receptor-positive tumors. In 1996 to 1999 and 2000 to 2002 invasive breast cancer incidence was higher for women who reported current HT use especially estrogen-progestin (EP) use at baseline than for never or past users; but by 2003 to 2005 rates were comparable between these groups. For women who were taking EP in 2001 to 2002,75% of whom had stopped use by 2005 to 2006, incidence had declined 30.6% by 2003 to 2005 (P = 0.001); whereas incidence did not change significantly for those who never took HT (P = 0.33).Few data resources can examine prospectively individual HT use and breast cancer diagnosis. Stable in situ breast cancer rates imply consistent levels of screening and suggest recent declines in invasive breast cancer to be explained predominantly by changes in HT use.

    View details for DOI 10.1186/bcr2467

    View details for Web of Science ID 000276986300010

    View details for PubMedID 20064209

  • Pregnancy-related factors and the risk of breast carcinoma in situ and invasive breast cancer among postmenopausal women in the California Teachers Study cohort BREAST CANCER RESEARCH Ma, H., Henderson, K. D., Sullivan-Halley, J., Duan, L., Marshall, S. F., Ursin, G., Horn-Ross, P. L., Largent, J., Deapen, D. M., Lacey, J. V., Bernstein, L. 2010; 12 (3)

    Abstract

    Although pregnancy-related factors such as nulliparity and late age at first full-term pregnancy are well-established risk factors for invasive breast cancer, the roles of these factors in the natural history of breast cancer development remain unclear.Among 52,464 postmenopausal women participating in the California Teachers Study (CTS), 624 were diagnosed with breast carcinoma in situ (CIS) and 2,828 with invasive breast cancer between 1995 and 2007. Multivariable Cox proportional hazards regression methods were used to estimate relative risks associated with parity, age at first full-term pregnancy, breastfeeding, nausea or vomiting during pregnancy, and preeclampsia.Compared with never-pregnant women, an increasing number of full-term pregnancies was associated with greater risk reduction for both breast CIS and invasive breast cancer (both P trend < 0.01). Women having four or more full-term pregnancies had a 31% lower breast CIS risk (RR = 0.69, 95% CI = 0.51 to 0.93) and 18% lower invasive breast cancer risk (RR = 0.82, 95% CI = 0.72 to 0.94). Parous women whose first full-term pregnancy occurred at age 35 years or later had a 118% greater risk for breast CIS (RR = 2.18, 95% CI = 1.36 to 3.49) and 27% greater risk for invasive breast cancer (RR = 1.27, 95% CI = 0.99 to 1.65) than those whose first full-term pregnancy occurred before age 21 years. Furthermore, parity was negatively associated with the risk of estrogen receptor-positive (ER+) or ER+/progesterone receptor-positive (PR+) while age at first full-term pregnancy was positively associated with the risk of ER+ or ER+/PR+ invasive breast cancer. Neither of these factors was statistically significantly associated with the risk of ER-negative (ER-) or ER-/PR- invasive breast cancer, tests for heterogeneity between subtypes did not reach statistical significance. No clear associations were detected for other pregnancy-related factors.These results provide some epidemiologic evidence that parity and age at first full-term pregnancy are involved in the development of breast cancer among postmenopausal women. The role of these factors in risk of in situ versus invasive, and hormone receptor-positive versus -negative breast cancer merits further exploration.

    View details for DOI 10.1186/bcr2589

    View details for Web of Science ID 000285689000011

    View details for PubMedID 20565829

  • Hidden Breast Cancer Disparities in Asian Women: Disaggregating Incidence Rates by Ethnicity and Migrant Status AMERICAN JOURNAL OF PUBLIC HEALTH Gomez, S. L., Quach, T., Horn-Ross, P. L., Pham, J. T., Cockburn, M., Chang, E. T., Keegan, T. H., Glaser, S. L., Clarke, C. A. 2010; 100: S125-S131

    Abstract

    We estimated trends in breast cancer incidence rates for specific Asian populations in California to determine if disparities exist by immigrant status and age.To calculate rates by ethnicity and immigrant status, we obtained data for 1998 through 2004 cancer diagnoses from the California Cancer Registry and imputed immigrant status from Social Security Numbers for the 26% of cases with missing birthplace information. Population estimates were obtained from the 1990 and 2000 US Censuses.Breast cancer rates were higher among US- than among foreign-born Chinese (incidence rate ratio [IRR] = 1.84; 95% confidence interval [CI] = 1.72, 1.96) and Filipina women (IRR = 1.32; 95% CI = 1.20, 1.44), but similar between US- and foreign-born Japanese women. US-born Chinese and Filipina women who were younger than 55 years had higher rates than did White women of the same age. Rates increased over time in most groups, as high as 4% per year among foreign-born Korean and US-born Filipina women. From 2000-2004, the rate among US-born Filipina women exceeded that of White women.These findings challenge the notion that breast cancer rates are uniformly low across Asians and therefore suggest a need for increased awareness, targeted cancer control, and research to better understand underlying factors.

    View details for DOI 10.2105/AJPH.2009.163931

    View details for Web of Science ID 000275937600025

    View details for PubMedID 20147696

  • Body Size, Recreational Physical Activity, and B-Cell Non-Hodgkin Lymphoma Risk Among Women in the California Teachers Study AMERICAN JOURNAL OF EPIDEMIOLOGY Lu, Y., Prescott, J., Sullivan-Halley, J., Henderson, K. D., Ma, H., Chang, E. T., Clarke, C. A., Horn-Ross, P. L., Ursin, G., Bernstein, L. 2009; 170 (10): 1231-1240

    Abstract

    Nutritional status and physical activity are known to alter immune function, which may be relevant to lymphomagenesis. The authors examined body size measurements and recreational physical activity in relation to risk of B-cell non-Hodgkin lymphoma (NHL) in the prospective California Teachers Study. Between 1995 and 2007, 574 women were diagnosed with incident B-cell NHL among 121,216 eligible women aged 22-84 years at cohort entry. Multivariable-adjusted relative risks and 95% confidence intervals were estimated by fitting Cox proportional hazards models for all B-cell NHL combined and for the 3 most common subtypes: diffuse large B-cell lymphoma, follicular lymphoma, and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma. Height was positively associated with risk of all B-cell NHLs (for >1.70 vs. 1.61-1.65 m, relative risk = 1.50, 95% confidence interval: 1.16, 1.96) and chronic lymphocytic leukemia/small lymphocytic lymphoma (relative risk = 1.93, 95% confidence interval: 1.09, 3.41). Weight and body mass index at age 18 years were positive predictors of B-cell NHL risk overall. These findings indicate that greater height, which may reflect genetics, early life immune function, infectious exposures, nutrition, or growth hormone levels, may play a role in NHL etiology. Adiposity at age 18 years may be more relevant to NHL etiology than that in later life.

    View details for DOI 10.1093/aje/kwp268

    View details for Web of Science ID 000271379800005

    View details for PubMedID 19822569

  • Obesity, waist size and prevalence of current asthma in the California Teachers Study cohort THORAX Von Behren, J., Lipsett, M., Horn-Ross, P. L., Delfino, R. J., Gilliland, F., McConnell, R., Bernstein, L., Clarke, C. A., Reynolds, P. 2009; 64 (10): 889-893

    Abstract

    Obesity is a risk factor for asthma, particularly in women, but few cohort studies have evaluated abdominal obesity which reflects metabolic differences in visceral fat known to influence systemic inflammation. A study was undertaken to examine the relationship between the prevalence of asthma and measures of abdominal obesity and adult weight gain in addition to body mass index (BMI) in a large cohort of female teachers.Prevalence odds ratios (ORs) for current asthma were calculated using multivariable linear modelling, adjusting for age, smoking and race/ethnicity.Of the 88 304 women in the analyses, 13% (n = 11,500) were obese (BMI > or = 30 kg/m(2)) at baseline; 1334 were extremely obese (BMI > or = 40 kg/m(2)). Compared with those of normal weight, the adjusted OR for adult-onset asthma increased from 1.40 (95% confidence interval (CI) 1.31 to 1.49) for overweight women to 3.30 (95% CI 2.85 to 3.82) for extremely obese women. Large waist circumference (>88 cm) was associated with increased asthma prevalence, even among women with a normal BMI (OR 1.37, 95% CI 1.18 to 1.59). Among obese women the OR for asthma was greater in those who were also abdominally obese than in women whose waist was < or = 88 cm (2.36 vs 1.57). Obese and overweight women were at greater risk of severe asthma episodes, measured by urgent medical visits and hospital admissions.This study confirms the association between excess weight and asthma severity and prevalence, and showed that a large waist was associated with increased asthma prevalence even among women considered to have normal body weight.

    View details for DOI 10.1136/thx.2009.114579

    View details for Web of Science ID 000270269700014

    View details for PubMedID 19706838

  • Second Primary Breast Cancer Occurrence According to Hormone Receptor Status JOURNAL OF THE NATIONAL CANCER INSTITUTE Kurian, A. W., McClure, L. A., John, E. M., Horn-Ross, P. L., Ford, J. M., Clarke, C. A. 2009; 101 (15): 1058-1065

    Abstract

    Contralateral second primary breast cancers occur in 4% of female breast cancer survivors. Little is known about differences in risk for second primary breast cancers related to the estrogen and progesterone receptor (hormone receptor [HR]) status of the first tumor.We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for contralateral primary breast cancers among 4927 women diagnosed with a first breast cancer between January 1, 1992, and December 31, 2004, using the National Cancer Institute's Surveillance, Epidemiology, and End Results database.For women whose first breast tumors were HR positive, risk of contralateral primary breast cancer was elevated, compared with the general population, adjusted for age, race, and calendar year (SIR = 2.22, 95% CI = 2.15 to 2.29, absolute risk [AR] = 13 cases per 10 000 person-years [PY]), and was not related to the HR status of the second tumor. For women whose first breast tumors were HR negative, the risk of a contralateral primary tumor was statistically significantly higher than that for women whose first tumors were HR positive (SIR = 3.57, 95% CI = 3.38 to 3.78, AR = 18 per 10 000 PY), and it was associated with a much greater likelihood of an HR-negative second tumor (SIR for HR-positive second tumors = 1.94, 95% CI = 1.77 to 2.13, AR = 20 per 10 000 PY; SIR for HR-negative second tumors = 9.81, 95% CI = 9.00 to 10.7, AR = 24 per 10 000 PY). Women who were initially diagnosed with HR-negative tumors when younger than 30 years had greatly elevated risk of HR-negative contralateral tumors, compared with the general population (SIR = 169, 95% CI = 106 to 256, AR = 77 per 10 000 PY). Incidence rates for any contralateral primary cancer following an HR-negative or HR-positive tumor were higher in non-Hispanic blacks, Hispanics, and Asians or Pacific Islanders than in non-Hispanic whites.Risk for contralateral second primary breast cancers varies substantially by HR status of the first tumor, age, and race and/or ethnicity. Women with HR-negative first tumors have nearly a 10-fold elevated risk of developing HR-negative second tumors, compared with the general population. These findings warrant intensive surveillance for second breast cancers in women with HR-negative tumors.

    View details for DOI 10.1093/jnci/djp181

    View details for Web of Science ID 000268812900007

    View details for PubMedID 19590058

  • Maximizing resources to study an uncommon cancer: E2C2-Epidemiology of Endometrial Cancer Consortium CANCER CAUSES & CONTROL Olson, S. H., Chen, C., De Vivo, I., Doherty, J. A., Hartmuller, V., Horn-Ross, P. L., Lacey, J. V., Lynch, S. M., Sansbury, L., Setiawan, V. W., Schouten, L. J., Shu, X. O. 2009; 20 (4): 491-496

    Abstract

    Endometrial cancer affects more than 40,000 women a year in the U.S. While the association of this disease with high body mass index and sex steroid hormones is well known, there are many questions about etiology that have not been resolved. Little is known about the genetic basis for risk associated with hormones or obesity, other common genetic factors associated with risk, or gene-environment interactions. E2C2, the Epidemiology of Endometrial Cancer Consortium, was formed in 2006 to provide a collaborative environment for addressing these questions by pooling data from existing studies. This allows for investigations of uncommon risk factors, risk for rare histologic subtypes, and associations within strata that cannot be achieved in individual studies. This report describes the establishment of the consortium, ongoing projects that demonstrate the advantages of collaborative efforts, and challenges faced. Overall, the consortium promises to provide an important means of furthering our knowledge about this cancer.

    View details for DOI 10.1007/s10552-008-9290-y

    View details for Web of Science ID 000265018900008

    View details for PubMedID 19132539

  • Two Estrogen-Related Variants in CYP19A1 and Endometrial Cancer Risk: A Pooled Analysis in the Epidemiology of Endometrial Cancer Consortium CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Setiawan, V. W., Doherty, J. A., Shu, X., Akbari, M. R., Chen, C., De Vivo, I., DeMichele, A., Garcia-Closas, M., Goodman, M. T., Haiman, C. A., Hankinson, S. E., Henderson, B. E., Horn-Ross, P. L., Lacey, J. V., Le Marchand, L., Levine, D. A., Liang, X., Lissowska, J., Lurie, G., McGrath, M., Narod, S. A., Rebbeck, T. R., Ursin, G., Weiss, N. S., Xiang, Y., Yang, H. P., Zheng, W., Olson, S. H. 2009; 18 (1): 242-247

    Abstract

    Common variants in CYP19A1 (the A alleles of rs749292 and rs727479) have been associated with a 10% to 20% increase in circulating estrogen levels in postmenopausal women. We hypothesized that the presence of one or both A alleles in these single nucleotide polymorphisms (SNP) is associated with increased endometrial cancer risk. We tested this hypothesis in a large pooled analysis of 4,998 endometrial cancer cases and 8,285 controls from 10 studies in the Epidemiology of Endometrial Cancer Consortium. The majority of women (>66%) were whites, with smaller proportions of other races and ethnic groups (blacks, Asians, and Latinas) also included in this pooled analysis. Unconditional logistic regression was used to model the association between SNPs/haplotypes and endometrial cancer risk. Carrying the A allele of either of these SNPs was associated with an increased risk of endometrial cancer, with pooled odds ratios per allele of 1.14, 95% confidence interval of 1.09-1.21, and P = 7.1 x 10(-7) for rs749292, and odds ratio per allele of 1.08, 95% confidence interval of 1.02-1.14, and P = 0.009 for rs727479. For rs749292, these associations were generally stronger among women age >or=55 years. For both SNPs, risk increased with increasing body mass index, and for rs727479, this pattern seemed stronger among women age >or=55 years (P interaction = 0.007). The combination of A alleles in the two SNPs, either by direct count or by haplotype analysis, did not increase risk above that observed for the individual SNPs. Our study provides evidence that CYP19A1 genetic variation influences susceptibility to endometrial cancer, particularly among older and obese women.

    View details for DOI 10.1158/1055-9965.EPI-08-0689

    View details for Web of Science ID 000262424200031

    View details for PubMedID 19124504

  • Risk of second primary breast cancers among women with ductal carcinoma in situ of the breast BREAST CANCER RESEARCH AND TREATMENT Innos, K., Horn-Ross, P. L. 2008; 111 (3): 531-540

    Abstract

    The diagnosis of ductal carcinoma in situ (DCIS) has become increasingly common, but it is not clear which factors predict the development of subsequent breast cancers in these women. The risk of second primary breast tumors was examined in a large, ethnically diverse population-based cohort of women with DCIS. METHODS; California Cancer Registry data on 23,547 women with first DCIS diagnosed in 1988-1999 were examined to estimate the incidence of second DCIS and invasive breast cancer relative to women in the general population. Relative risks were calculated using Poisson regression to estimate which women with DCIS were likely to develop a second DCIS or invasive breast cancer.Compared to the general population, women with DCIS had significantly increased risk of contralateral DCIS (standardized incidence ratio [SIR] 4.2, 95% confidence interval [CI] 3.7-4.7), contralateral invasive cancer (SIR 1.4, 95% CI 1.2-1.5), ipsilateral DCIS (SIR 4.2, 95% CI 3.5-5.0), and ipsilateral invasive cancer (SIR 1.7, 95% CI 1.4-2.1). Variation by race/ethnicity, age, time, and tumor and treatment characteristics were observed. Black women were 1.9-fold more likely to develop ipsilateral invasive cancer than white women. Young age at onset, comedo histology and having received partial mastectomy only or having neither surgical nor radiation treatment for first DCIS were predictive of ipsilateral cancers.Close follow-up of women with DCIS is warranted, particularly those who are Black or diagnosed at young age. Investigations should continue to clarify the underlying mechanisms of racial, age, and other differences in second cancer risk.

    View details for DOI 10.1007/s10549-007-9807-1

    View details for Web of Science ID 000259126300017

    View details for PubMedID 17978879

  • Adenomyosis and endometriosis in the California Teachers Study FERTILITY AND STERILITY Templeman, C., Marshall, S. F., Ursin, G., Horn-Ross, P. L., Clarke, C. A., Allen, M., Deapen, D., Ziogas, A., Reynolds, P., Cress, R., Anton-Culver, H., West, D., Ross, R. K., Bernstein, L. 2008; 90 (2): 415-424

    Abstract

    To evaluate the reproductive and lifestyle correlates of a surgically confirmed diagnosis of endometriosis or adenomyosis in a large prospective cohort.Collection of surgical diagnoses of endometriosis and adenomyosis during follow-up of women with no prior history of endometriosis and no prior surgery for adenomyosis.The California Teachers Study (CTS), an ongoing prospective study of female teachers and school administrators established from the rolls of the California State Teachers Retirement System.Women with surgical diagnoses of endometriosis and adenomyosis were identified from California statewide hospital patient discharge records for CTS cohort members with an intact uterus and no prior history of endometriosis. Women with an incident surgical diagnosis of endometriosis (n = 229) or adenomyosis (n = 961) were compared with disease-free women in the same age range (for endometriosis, n = 43,493; for adenomyosis, n = 79,495).None.Multivariable logistic regression methods were used to calculate prevalence odds ratios and associated 95% confidence intervals for the associations between self-reported menstrual and reproductive characteristics and either endometriosis or adenomyosis.Women surgically diagnosed with endometriosis were younger than those surgically diagnosed with adenomyosis. Factors statistically significantly associated with endometriosis were having a mother or sister with endometriosis and nulligravidity. Factors statistically significantly associated with adenomyosis were increasing parity, early menarche (

    View details for DOI 10.1016/j.fertnstert.2007.06.027

    View details for Web of Science ID 000258483800028

    View details for PubMedID 17919609

  • Dietary assessment in the California Teachers Study: reproducibility and validity CANCER CAUSES & CONTROL Horn-Ross, P. L., Lee, V. S., Collins, C. N., Stewart, S. L., Canchola, A. J., Lee, M. M., Reynolds, P., Clarke, C. A., Bernstein, L., Stram, D. O. 2008; 19 (6): 595-603

    Abstract

    To evaluate the reproducibility and validity of the food-frequency questionnaire (FFQ) used in the California Teachers Study (CTS) cohort and to use this data to quantify the effects of correcting nutrient-breast cancer relative risks for measurement error.One hundred and ninety five CTS cohort members participated in a 10-month dietary validation study that included four 24-h dietary recalls and pre- and post-study FFQs. Shrout-Fleiss intraclass correlations for reproducibility were computed. Under several standard assumptions concerning the correlations of errors in the FFQs and 24-h recalls, we calculated energy-adjusted deattenuated Pearson correlations for validity and tested for differences in validity according to a number of demographic and other risk factors. For each nutrient, we compared the performance of the FFQ versus the 24-h recalls, estimating the number of days of recalls that give equivalent information about true intake as does a single FFQ. Finally, the effects of adjustment for measurement error on risk estimates were evaluated in 44,423 postmenopausal cohort members, 1,544 of whom developed breast cancer during seven years of follow-up. Relative risks (RR) and confidence intervals (CI) were calculated using Cox proportional hazards with and without correction for measurement error.Reproducibility correlations for the nutrients ranged from 0.60 to 0.87. With a few exceptions, validity correlations were reasonably high (range: 0.55-0.85), including r = 0.74 for alcohol. Performance of the FFQ differed by age for percent of calories from fat and by body mass index and hormone therapy use for alcohol consumption. For most nutrients examined, our FFQ is comparable to two to six recalls for each subject in capturing true intake. In the measurement error-adjusted risk analyses, corrected RRs were within 13% of uncorrected values for all nutrients examined except for linoleic acid. For alcohol consumption the corrected RR (per 20 g/1,000 kcal/d) was 1.36 (95% CI: 1.03-1.51) compared to the uncorrected estimate of 1.25 (95% CI: 1.10-1.42).The FFQ dietary assessment used in the CTS is reproducible and valid for all nutrients except the unsaturated fatty acids. Correcting relative risk estimates for measurement error resulted in relatively small changes in the associations between the majority of nutrients and the risk of postmenopausal breast cancer.

    View details for DOI 10.1007/s10552-008-9124-y

    View details for Web of Science ID 000257327300006

    View details for PubMedID 18256894

  • Dietary fat, cooking fat, and breast cancer risk in a multiethnic population NUTRITION AND CANCER-AN INTERNATIONAL JOURNAL Wang, J., John, E. M., Horn-Ross, P. L., Ingles, S. A. 2008; 60 (4): 492-504

    Abstract

    Our objective was to examine the association between dietary fat intake, cooking fat usage, and breast cancer risk in a population-based, multiethnic, case-control study conducted in the San Francisco Bay area. Intake of total fat and types of fat were assessed with a food frequency questionnaire among 1,703 breast cancer cases diagnosed between 1995 and 1999 and 2,045 controls. In addition, preferred use of fat for cooking was assessed. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). High fat intake was associated with increased risk of breast cancer (highest vs. lowest quartile, adjusted OR = 1.35, 95% CI = 1.10-1.65, P(trend) < 0.01). A positive association was found for oleic acid (OR = 1.55, 95% CI = 1.14-2.10, P(trend) < 0.01) but not for linoleic acid or saturated fat. Risk was increased for women cooking with hydrogenated fats (OR = 1.58, 95% CI = 1.20-2.10) or vegetable/corn oil (rich in linoleic acid; OR = 1.30, 95% CI = 1.06-1.58) compared to women using olive/canola oil (rich in oleic acid). Our results suggest that a low-fat diet may play a role in breast cancer prevention. We speculate that monounsaturated trans fats may have driven the discrepant associations between types of fat and breast cancer.

    View details for DOI 10.1080/01635580801956485

    View details for Web of Science ID 000257988700008

    View details for PubMedID 18584483

  • Incomplete pregnancy is not associated with breast cancer risk: the California Teachers Study CONTRACEPTION Henderson, K. D., Sullivan-Halley, J., Reynolds, P., Horn-Ross, P. L., Clarke, C. A., Chang, E. T., Neuhausen, S., Ursin, G., Bernstein, L. 2008; 77 (6): 391-396

    Abstract

    Early studies of incomplete pregnancy and development of breast cancer suggested that induced abortion might increase risk. Several large prospective studies, which eliminate recall bias, did not detect associations, but this relationship continues to be debated.To further inform this important question, we examined invasive breast cancer as it relates to incomplete pregnancy, including total number of induced abortions, age at first induced abortion and total number of miscarriages among women participating in the ongoing California Teachers Study (CTS) cohort. Incomplete pregnancy was self-reported on the CTS baseline questionnaire in 1995-1996. Incident breast cancers were ascertained in 3324 women through 2004 via linkage with the California Cancer Registry.Using Cox multivariable regression, we found no statistically significant association between any measure of incomplete pregnancy and breast cancer risk among nulliparous or parous women.These results provide strong evidence that there is no relationship between incomplete pregnancy and breast cancer risk.

    View details for DOI 10.1016/j.contraception.2008.02.004

    View details for Web of Science ID 000256136200002

    View details for PubMedID 18477486

  • Dietary patterns and risk of ovarian cancer in the California Teachers Study Cohort NUTRITION AND CANCER-AN INTERNATIONAL JOURNAL Chang, E. T., Lee, V. S., Canchola, A. J., Dalvi, T. B., Clarke, C. A., Reynolds, P., Purdie, D. M., Stram, D. O., West, D. W., Ziogas, A., Bernstein, L., Horn-Ross, P. L. 2008; 60 (3): 285-291

    Abstract

    Previous studies have examined the association between individual foods or nutrients, but not overall diet, and ovarian cancer risk. To account for the clustering of foods in the diet, we investigated the association between dietary patterns and risk of ovarian cancer in the prospective California Teachers Study cohort. Of 97,292 eligible women who completed the baseline dietary assessment in 1995-1996, 311 women developed epithelial ovarian cancer on or before December 31, 2004. Based on principal components analysis, 5 major dietary patterns were identified and termed plant-based, high-protein/high-fat, high-carbohydrate, ethnic, and salad-and-wine. Multivariable Cox proportional hazards regression analysis was used to estimate associations between these dietary patterns and risk of incident ovarian cancer. Most of the dietary patterns were not significantly associated with ovarian cancer risk. However, women who followed a plant-based diet had higher risk; comparing those in the top quintile of plant-based food intake with those in the lowest quintile, the relative risk of ovarian cancer was 1.65 (95% confidence interval = 1.07-2.54; P(trend) = 0.03). Associations with the 5 dietary patterns did not vary by known ovarian cancer risk factors or other behavioral or sociodemographic characteristics. Overall, our results show no convincing associations between dietary patterns and ovarian cancer risk.

    View details for DOI 10.1080/01635580701733091

    View details for Web of Science ID 000256439800001

    View details for PubMedID 18444162

  • Dietary patterns, Mediterranean diet, and endometrial cancer risk CANCER CAUSES & CONTROL Dalvi, T. B., Canchola, A. J., Horn-Ross, P. L. 2007; 18 (9): 957-966

    Abstract

    This study examines the association between dietary patterns and endometrial cancer risk. A case-control study of endometrial cancer was conducted from 1996 to 1999 in the San Francisco Bay Area in white, African-American, and Latina women age 35-79. Dietary patterns were defined using a principal components analysis; scoring dietary intake based on correspondence to a Mediterranean-style diet; and by jointly categorizing intake of fruits/vegetables and dietary fat. Four dietary patterns were identified and labeled "plant-based," "western," "ethnic," and "phytoestrogen-rich." None of these dietary patterns nor adherence to a Mediterranean diet (to the extent consumed by this population) was associated with endometrial cancer risk. However, among non-users of supplements, greater consumption of the "western" dietary pattern was associated with a 60% increase in risk (95% CI: 0.95-2.7 per unit change; P-interaction = 0.10). A diet characterized by high fat consumption increased risk, regardless of fruit and vegetable consumption (OR = 1.4, 95% CI: 0.97-2.1 for high fat, low fruit/vegetable intake and OR = 1.4, 95% CI: 0.95-2.1 for high fat, high fruit/vegetable intake compared to low fat, high fruit/vegetable intake). Thus, while like others we found that dietary fat increases endometrial cancer risk, the evaluation of dietary patterns did not provide any additional information regarding risk.

    View details for DOI 10.1007/s10552-007-9037-1

    View details for Web of Science ID 000248805700006

    View details for PubMedID 17638105

  • Germ line variation at 8q24 and endometrial cancer risk CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Setiawan, V. W., Ursin, G., Horn-Ross, P. L., Van Den Berg, D., Le Marchand, L., Henderson, B. E., Bernstein, L., Haiman, C. A. 2007; 16 (10): 2166-2168
  • Alcohol intake and renal cell cancer in a pooled analysis of 12 prospective studies JOURNAL OF THE NATIONAL CANCER INSTITUTE Lee, J. E., Hunter, D. J., Spiegelman, D., Adami, H., Albanes, D., Bernstein, L., van den Brandt, P. A., Buring, J. E., Cho, E., Folsom, A. R., Freudenheim, J. L., Giovannucci, E., Graham, S., Horn-Ross, P. L., Leitzmann, M. F., McCullough, M. L., Miller, A. B., Parker, A. S., Rodriguez, C., Rohan, T. E., Schatzkin, A., Schouten, L. J., Virtanen, M., Willett, W. C., Wolk, A., Zhang, S. M., Smith-Warner, S. A. 2007; 99 (10): 801-810

    Abstract

    The association between alcohol intake and risk of renal cell cancer has been inconsistent in case-control studies. An inverse association between alcohol intake and risk of renal cell cancer has been suggested in a few prospective studies, but each of these studies included a small number of cases.We performed a pooled analysis of 12 prospective studies that included 530,469 women and 229,575 men with maximum follow-up times of 7-20 years. All participants had completed a validated food-frequency questionnaire at baseline. Using the primary data from each study, the study-specific relative risks (RRs) for renal cell cancer were calculated using Cox proportional hazards models and then pooled using a random-effects model. All statistical tests were two-sided.A total of 1430 (711 women and 719 men) cases of incident renal cell cancer were identified. The study-standardized incidence rates of renal cell cancer were 23 per 100,000 person-years among nondrinkers and 15 per 100,000 person-years among those who drank 15 g/day or more of alcohol. Compared with nondrinking, alcohol consumption (> or = 15 g/day, equivalent to slightly more than one alcoholic drink per day) was associated with a decreased risk of renal cell cancer (pooled multivariable RR = 0.72, 95% confidence interval = 0.60 to 0.86; P(trend)<.001); statistically significant inverse trends with increasing intake were seen in both women and men. No difference by sex was observed (P(heterogeneity) = .89). Associations between alcohol intake and renal cell cancer were not statistically different across alcoholic beverage type (beer versus wine versus liquor) (P = .40).Moderate alcohol consumption was associated with a lower risk of renal cell cancer among both women and men in this pooled analysis.

    View details for Web of Science ID 000246694000011

    View details for PubMedID 17505075

  • Diet and risk of ovarian cancer in the California teachers study cohort AMERICAN JOURNAL OF EPIDEMIOLOGY Chang, E. T., Lee, V. S., Canchola, A. J., Clarke, C. A., Purdie, D. M., Reynolds, P., Anton-Culver, H., Bernstein, L., Deapen, D., Peel, D., Pinder, R., Ross, R. K., Stram, D. O., West, D. W., Wright, W., Ziogas, A., Horn-Ross, P. L. 2007; 165 (7): 802-813

    Abstract

    Dietary phytochemical compounds, including isoflavones and isothiocyanates, may inhibit cancer development but have not yet been examined in prospective epidemiologic studies of ovarian cancer. The authors have investigated the association between consumption of these and other nutrients and ovarian cancer risk in a prospective cohort study. Among 97,275 eligible women in the California Teachers Study cohort who completed the baseline dietary assessment in 1995-1996, 280 women developed invasive or borderline ovarian cancer by December 31, 2003. Multivariable Cox proportional hazards regression, with age as the timescale, was used to estimate relative risks and 95% confidence intervals; all statistical tests were two sided. Intake of isoflavones was associated with lower risk of ovarian cancer. Compared with the risk for women who consumed less than 1 mg of total isoflavones per day, the relative risk of ovarian cancer associated with consumption of more than 3 mg/day was 0.56 (95% confidence interval: 0.33, 0.96). Intake of isothiocyanates or foods high in isothiocyanates was not associated with ovarian cancer risk, nor was intake of macronutrients, antioxidant vitamins, or other micronutrients. Although dietary consumption of isoflavones may be associated with decreased ovarian cancer risk, most dietary factors are unlikely to play a major role in ovarian cancer development.

    View details for DOI 10.1093/aje/kwk065

    View details for Web of Science ID 000244959600010

    View details for PubMedID 17210953

  • Physical activity and colon cancer risk among women in the california teachers study CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Mai, P. L., Sullivan-Halley, J., Ursin, G., Stram, D. O., Deapen, D., Villaluna, D., Horn-Ross, P. L., Clarke, C. A., Reynolds, P., Ross, R. K., West, D. W., Anton-Culver, H., Ziogas, A., Bernstein, L. 2007; 16 (3): 517-525

    Abstract

    Existing data suggest that physical activity reduces colon cancer risk, but the association is not consistently observed in women. One potential explanation for this inconsistency is that hormone therapy, which is associated with lower colon cancer risk, acts as a modifier of the physical activity/colon cancer relationship.Participants in the California Teachers Study (N = 120,147), a prospective cohort of female teachers and administrators residing in California, ages 22 to 84 years at baseline and with no prior history of colon cancer were eligible for study. Between 1996 and 2002, 395 patients were diagnosed with invasive colon cancer. The relative risks (RR) associated with lifetime (high school through age 54 years or current age) and recent (past 3 years) strenuous and moderate recreational physical activity were estimated using Cox proportional hazards regression models.Combined lifetime moderate and strenuous recreational physical activity was only modestly associated with colon cancer risk in the cohort [>or=4 versus or=4 versus

    View details for DOI 10.1158/1055-9965.EPI-06-0747

    View details for Web of Science ID 000245093900027

    View details for PubMedID 17372247

  • Long-term recreational physical activity and risk of invasive and in situ breast cancer - The California teachers study ARCHIVES OF INTERNAL MEDICINE Dallal, C. M., Sullivan-Halley, J., Ross, R. K., Wang, Y., Deapen, D., Horn-Ross, P. L., Reynolds, P., Stram, D. O., Clarke, C. A., Anton-Culver, H., Ziogas, A., Peel, D., West, D. W., Wright, W., Bernstein, L. 2007; 167 (4): 408-415

    Abstract

    Long-term physical activity may affect breast cancer risk. Few prospective studies have evaluated in situ or invasive breast cancer risk, or breast cancer receptor subtypes, in relation to long-term activity.We examined the association between recreational physical activity and risk of invasive and in situ breast cancer in the California Teachers Study, a cohort of women established in 1995-1996. Of 110 599 women aged 20 to 79 years with no history of breast cancer followed up through December 31, 2002, 2649 were diagnosed as having incident invasive breast cancer and 593 were diagnosed as having in situ breast cancer. Information was collected at cohort entry on participation in strenuous and moderate recreational activities during successive periods from high school through the current age or age 54 years (if older at enrollment) and in the past 3 years. A summary measure of long-term activity up to the current age, or age 54 years if older, was constructed for each woman.Invasive breast cancer risk was inversely associated with long-term strenuous activity (>5 vs 5 vs

    View details for Web of Science ID 000244467000020

    View details for PubMedID 17325304

  • Wine and other alcohol consumption and risk of ovarian cancer in the California Teachers Study cohort CANCER CAUSES & CONTROL Chang, E. T., Canchola, A. J., Lee, V. S., Clarke, C. A., Purdie, D. M., Reynolds, P., Bernstein, L., Stram, D. O., Anton-Culver, H., Deapen, D., Mohrenweiser, H., Peel, D., Pinder, R., Ross, R. K., West, D. W., Wright, W., Ziogas, A., Horn-Ross, P. L. 2007; 18 (1): 91-103

    Abstract

    Whether alcohol consumption influences ovarian cancer risk is unclear. Therefore, we investigated the association between alcohol intake at various ages and risk of ovarian cancer.Among 90,371 eligible members of the California Teachers Study cohort who completed a baseline alcohol assessment in 1995-1996, 253 women were diagnosed with epithelial ovarian cancer by the end of 2003. Multivariate Cox proportional hazards regression analysis was performed to estimate relative risks (RRs) and 95% confidence intervals (CIs).Consumption of total alcohol, beer, or liquor in the year prior to baseline, at ages 30-35 years, or at ages 18-22 years was not associated with risk of ovarian cancer. Consumption of at least one glass per day of wine, compared to no wine, in the year before baseline was associated with increased risk of developing ovarian cancer: RR = 1.57 (95% CI 1.11-2.22), P (trend) = 0.01. The association with wine intake at baseline was particularly strong among peri-/post-menopausal women who used estrogen-only hormone therapy and women of high socioeconomic status.Alcohol intake does not appear to affect ovarian cancer risk. Constituents of wine other than alcohol or, more likely, unmeasured determinants of wine drinking were associated with increased risk of ovarian cancer.

    View details for DOI 10.1007/s10552-006-0083-x

    View details for Web of Science ID 000243031800009

    View details for PubMedID 17186425

  • Recent changes in breast cancer incidence and risk factor prevalence in San Francisco Bay area and California women: 1988 to 2004 BREAST CANCER RESEARCH Keegan, T. H., Chang, E. T., John, E. M., Horn-Ross, P. L., Wrensch, M. R., Glaser, S. L., Clarke, C. A. 2007; 9 (5)

    Abstract

    Historically, the incidence rate of breast cancer among non-Hispanic white women living in the San Francisco Bay area (SFBA) of California has been among the highest in the world. Substantial declines in breast cancer incidence rates have been documented in the United States and elsewhere during recent years. In light of these reports, we examined recent changes in breast cancer incidence and risk factor prevalence among non-Hispanic white women in the SFBA and other regions of California.Annual age-adjusted breast cancer incidence and mortality rates (1988 to 2004) were obtained from the California Cancer Registry and analyzed using Joinpoint regression. Population-based risk factor prevalences were calculated using two data sources: control subjects from four case-control studies (1989 to 1999) and the 2001 and 2003 California Health Interview Surveys.In the SFBA, incidence rates of invasive breast cancer increased 1.3% per year (95% confidence interval [CI], 0.7% to 2.0%) in 1988-1999 and decreased 3.6% per year (95% CI, 1.6% to 5.6%) in 1999-2004. In other regions of California, incidence rates of invasive breast cancer increased 0.8% per year (95% CI, 0.4% to 1.1%) in 1988-2001 and decreased 4.4% per year (95% CI, 1.4% to 7.3%) in 2001-2004. In both regions, recent (2000-2001 to 2003-2004) decreases in invasive breast cancer occurred only in women 40 years old or older and in women with all histologic subtypes and tumor sizes, hormone receptor-defined types, and all stages except distant disease. Mortality rates declined 2.2% per year (95% CI, 1.8% to 2.6%) from 1988 to 2004 in the SFBA and the rest of California. Use of estrogen-progestin hormone therapy decreased significantly from 2001 to 2003 in both regions. In 2003-2004, invasive breast cancer incidence remained higher (4.2%) in the SFBA than in the rest of California, consistent with the higher distributions of many established risk factors, including advanced education, nulliparity, late age at first birth, and alcohol consumption.Ongoing surveillance of breast cancer occurrence patterns in this high-risk population informs breast cancer etiology through comparison of trends with lower-risk populations and by highlighting the importance of examining how broad migration patterns influence the geographic distribution of risk factors.

    View details for DOI 10.1186/bcr1768

    View details for Web of Science ID 000253285800011

    View details for PubMedID 20210979

  • Estimating exposure to polycyclic aromatic hydrocarbons: A comparison of survey, biological monitoring, and geographic information system-based methods CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Gunier, R. B., Reynolds, P., Hurley, S. E., Yerabati, S., Hertz, A., Strickland, P., Horn-Ross, P. L. 2006; 15 (7): 1376-1381

    Abstract

    Our objective was to compare polycyclic aromatic hydrocarbon (PAH) exposure estimates based on survey, biological monitoring, and geographic information system (GIS) methods. The 304 participants in this study supplied a urine sample and completed questionnaires about exposure to potential PAH sources. We assayed urine samples for 1-hydroxypyrene-O-glucuronide (1-OHPG), the major metabolite of pyrene, a common PAH. We used a GIS to estimate traffic exhaust exposure using vehicle count data at the residence and workplace. The five subjects who reported smoking during the 48-hour period had median 1-OHPG concentrations 10-fold that of nonsmokers (1.6 versus 0.16 pmol/mL; P = 0.01). Among nonsmokers, those who reported eating grilled, roasted, or broiled meat had significantly higher 1-OHPG concentrations than those who did not reported eating meat prepared by these methods (0.25 versus 0.06 pmol/mL; P = 0.02). Nonsmokers who reported traveling on roads for > or =3 hours during the 48-hour period also had significantly higher 1-OHPG levels than those who traveled <3 hours (0.23 versus 0.11 pmol/mL; P = 0.03). 1-OHPG levels were also correlated with hours of secondhand smoke exposure among nonsmokers (P = 0.04). In this study, 1-OHPG urine concentrations were not associated with self-reported exposures to cooking smoke, wood burning, or traffic levels near the home or to traffic density or urban/rural status determined using a GIS. Self-reported indicators of residential proximity to high traffic volume were, however, associated with GIS traffic density measures.

    View details for Web of Science ID 000238880800023

    View details for PubMedID 16835339

  • Methods for pooling results of epidemiologic studies - The pooling project of prospective studies of diet and cancer AMERICAN JOURNAL OF EPIDEMIOLOGY Smith-Warner, S. A., Spiegelman, D., Ritz, J., Albanes, D., Beeson, W. L., Bernstein, L., Berrino, F., van den Brandt, P. A., Buring, J. E., Cho, E., Colditz, G. A., Folsom, A. R., Freudenheim, J. L., Giovannucci, E., Goldbohm, R. A., Graham, S., Harnack, L., Horn-Ross, P. L., Krogh, V., Leitzmann, M. F., McCullough, M. L., Miller, A. B., Rodriguez, C., Rohan, T. E., Schatzkin, A., Shore, R., Virtanen, M., Willett, W. C., Wolk, A., Zeleniuch-Jacquotte, A., Zhang, S. M., Hunter, D. J. 2006; 163 (11): 1053-1064

    Abstract

    With the growing number of epidemiologic publications on the relation between dietary factors and cancer risk, pooled analyses that summarize results from multiple studies are becoming more common. Here, the authors describe the methods being used to summarize data on diet-cancer associations within the ongoing Pooling Project of Prospective Studies of Diet and Cancer, begun in 1991. In the Pooling Project, the primary data from prospective cohort studies meeting prespecified inclusion criteria are analyzed using standardized criteria for modeling of exposure, confounding, and outcome variables. In addition to evaluating main exposure-disease associations, analyses are also conducted to evaluate whether exposure-disease associations are modified by other dietary and nondietary factors or vary among population subgroups or particular cancer subtypes. Study-specific relative risks are calculated using the Cox proportional hazards model and then pooled using a random- or mixed-effects model. The study-specific estimates are weighted by the inverse of their variances in forming summary estimates. Most of the methods used in the Pooling Project may be adapted for examining associations with dietary and nondietary factors in pooled analyses of case-control studies or case-control and cohort studies combined.

    View details for DOI 10.1093/aje/kwj127

    View details for Web of Science ID 000238051800012

    View details for PubMedID 16624970

  • Risk of second primary malignancies in women with papillary thyroid cancer AMERICAN JOURNAL OF EPIDEMIOLOGY Canchola, A. J., Horn-Ross, P. L., Purdie, D. M. 2006; 163 (6): 521-527

    Abstract

    Second malignancies in women diagnosed with thyroid cancer are of concern given the young average age at diagnosis and excellent survival. Data from the California Cancer Registry were used to evaluate the risk of second primary cancers among a retrospective population-based cohort of 10,932 women diagnosed with papillary thyroid cancer between 1988 and 1999. Follow-up was calculated from 2 months until the diagnosis of a second primary cancer, death, loss to follow-up, or December 31, 1999, whichever occurred first. Standardized incidence ratios, based on age-specific cancer incidence rates for California women, were calculated. During a total of 50,938 person-years of follow-up (mean: 4.7 years), 279 women developed a second primary cancer. The incidence of invasive breast cancer was not elevated compared with California women overall (standardized incidence ratio (SIR) = 0.9, 95% confidence interval (CI): 0.7, 1.1) or when stratified by age, race/ethnicity, follow-up, or radiation treatment. An excess of in situ breast cancer (SIR = 1.6, 95% CI: 1.0, 2.4), kidney cancer (SIR = 3.9, 95% CI: 2.2, 6.3), and melanoma (SIR = 2.1, 95% CI: 1.3, 3.2) limited to the first 5 years after diagnosis was observed. Women with papillary thyroid cancer are at increased risk of in situ, but not invasive, breast cancer, kidney cancer, and melanoma.

    View details for DOI 10.1093/aje/kwj072

    View details for Web of Science ID 000235770400004

    View details for PubMedID 16421240

  • Reliability and validity of an assessment of usual phytoestrogen consumption (United States) CANCER CAUSES & CONTROL Horn-Ross, P. L., Barnes, S., Lee, V. S., Collins, C. N., Reynolds, P., Lee, M. M., Stewart, S. L., Canchola, A. J., Wilson, L., Jones, K. 2006; 17 (1): 85-93

    Abstract

    To evaluate the reliability and validity of a food-frequency questionnaire (FFQ) and database designed to quantify phytoestrogen consumption.This study included 195 members of the California Teachers Study (CTS) cohort who, over a 10-month period, completed four 24-h dietary recalls, a pre- and post-study FFQ, and provided two 24-h urine specimens. Participants (n = 106) in a parallel study (and 18 women who dropped out of the long-term study) completed a single recall and FFQ, and provided one 24-h urine specimen. Urinary phytoestrogens were determined using liquid chromatography-mass spectrometry. Reliability and validity were evaluated using Shrout-Fleiss intraclass correlations and energy-adjusted deattenuated Pearson correlations, respectively.Correlations reflecting the reproducibility of the FFQ phytoestrogen assessment ranged from 0.67 to 0.81. Validity correlations (FFQ compared to dietary recalls) ranged from 0.67 to 0.79 for the major phytoestrogenic compounds (i.e., daidzein, genistein, and secoisolariciresinol) and 0.43 to 0.54 for the less common compounds. Compared to urinary levels, validity correlations ranged from 0.41 to 0.55 for the isoflavones and 0.16 to 0.21 for total lignans.Our isoflavone assessment is reproducible, valid, and an excellent tool for evaluating the relationship with disease risk in non-Asian populations. Further research is needed before these tools can accurately be used to assess lignan consumption.

    View details for DOI 10.1007/s10552-005-0391-6

    View details for Web of Science ID 000234825600012

    View details for PubMedID 16411057

  • Nonsteroidal anti-inflammatory drug use and breast cancer risk by stage and hormone receptor status JOURNAL OF THE NATIONAL CANCER INSTITUTE Marshall, S. F., Bernstein, L., Anton-Culver, H., Deapen, D., Horn-Ross, P. L., Mohrenweiser, H., Peel, D., Pinder, R., Purdie, D. M., Reynolds, P., Stram, D., West, D., Wright, W. E., Ziogas, A., Ross, R. K. 2005; 97 (11): 805-812

    Abstract

    Epidemiologic studies of the association between nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen, and breast cancer risk have yielded inconsistent results. We investigated the association of NSAID use with risk of breast cancer in the California Teachers Study cohort, with special attention to risk of specific breast cancer subtypes and to type of NSAID used.We analyzed data on 114 460 women in the California Teachers Study cohort who were aged 22 to 85 years and free of breast cancer at baseline in 1995 to 1996. Information on frequency and duration of NSAID use was collected through a self-administered questionnaire. A total of 2391 women were diagnosed with breast cancer during the follow-up period from 1995 to 2001. We used Cox proportional hazards regression to estimate relative risks (RR) and 95% confidence intervals (CI) of breast cancer subtypes with NSAID use.Neither regular use (more than once a week) of any NSAID (aspirin and ibuprofen combined) nor regular use of aspirin was associated with breast cancer risk (RR = 1.09, 95% CI = 0.97 to 1.21 for daily versus no regular use of NSAIDs and RR = 0.98, 95% CI = 0.86 to 1.13 for daily versus no regular use of aspirin). However, long-term (> or = 5 years) daily aspirin users had a non-statistically significant decreased risk of estrogen receptor and progesterone receptor (ER/PR)-positive breast cancer (RR = 0.80, 95% CI = 0.62 to 1.03). In contrast, we observed a statistically significantly increased risk of ER/PR-negative breast cancer with long-term daily use of aspirin (RR = 1.81, 95% CI = 1.12 to 2.92). In this population, 11 fewer ER/PR-positive breast cancer cases and seven excess ER/PR-negative breast cancer cases may be due to daily long-term aspirin use among 2391 breast cancer cases observed over 6 years if the association were proven to be causal. Long-term daily use of ibuprofen was also associated with an increased risk of breast cancer (RR = 1.51, 95% CI = 1.17 to 1.95), particularly of nonlocalized tumors (RR = 1.92, 95% CI = 1.24 to 2.97). If causality were subsequently proven, 16 of the observed 2391 breast cancer cases and 8 of the 713 non-localized breast cancer cases would be attributable to long-term daily use of ibuprofen.Long-term daily use of NSAIDs was not associated with breast cancer risk overall. Ibuprofen use was associated with an increased risk of breast cancer, and long-term daily aspirin use was associated with an increased risk of ER/PR-negative breast cancer. However, it is not clear if the observed association is causal.

    View details for DOI 10.1093/jnci.dji140

    View details for Web of Science ID 000229939000008

    View details for PubMedID 15928301

  • Residential mobility in the California Teachers Study: implications for geographic differences in disease rates SOCIAL SCIENCE & MEDICINE Hurley, S. E., Reynolds, P., Goldberg, D. E., Hertz, A., Anton-Culver, H., Bernstein, L., Deapen, D., Peel, D., Pinder, R., Ross, R. K., West, D., Wright, W. E., Ziogas, A., Horn-Ross, P. L. 2005; 60 (7): 1547-1555

    Abstract

    Especially for cancers with long latency periods, such as breast cancer, the issue of residential mobility hinders ecologic analyses seeking to examine the role of environmental contaminants in chronic disease etiology. This study describes and evaluates characteristics associated with residential mobility in a sub-sample of the California Teachers Study (CTS) cohort.In 2000, lifetime residential histories were collected for a sub-sample of 328 women enrolled in the CTS; women's degree of residential mobility and associated factors were analyzed.While most women moved many times during their lives (average = 8.9), the average number of years at their residence when they enrolled in the study was reasonably long (15.1 years). Age strongly predicted duration at current residence but was not related to the number of lifetime residences. After adjusting for age, California-born women and women living in high socioeconomic status (SES) neighborhoods were significantly more residentially stable. Agreement between self-reported urbanization of recent residences and that based on census data of the geocoded residences was very good (80% concordant). Among women currently living in urban areas, an average of 43.3 years, or 77%, of their lifetimes were spent in urban residences; among women currently living in a rural area, an average of 37.3 years, or 67% of their lifetimes were spent in rural residences.This suggests that analyses of incidence rates based on current residence, while not capturing a woman's full exposure history, may reasonably reflect some aspect of longer term chronic exposures, especially those related to urbanization, at least in professional women.

    View details for DOI 10.1016/j.socscimed.2004.07.018

    View details for Web of Science ID 000226714200012

    View details for PubMedID 15652686

  • Regional variations in breast cancer among California teachers EPIDEMIOLOGY Reynolds, P., Hurley, S., Goldberg, D. E., Anton-Culver, H., Bernstein, L., Deapen, D., Horn-Ross, P. L., Peel, D., Pinder, R., Ross, R. K., West, D., Wright, W. E., Ziogas, A. 2004; 15 (6): 746-754

    Abstract

    Observed regional differences in breast cancer incidence could provide valuable clues to the etiology of this disease. The pattern of historically higher breast cancer rates among residents of California's San Francisco Bay and Southern Coastal areas is evident in the disease experience among members of the California Teachers Study. This large cohort study has followed female professional school employees for cancer incidence since 1995 and has collected extensive information on breast cancer risk factors.Between 1996 and 1999, invasive breast cancer was diagnosed in 1562 of the 115,611 cohort members who could be geocoded to a California address in 1995 and who had no previous breast cancer diagnosis. Adjusted hazard rate ratios (HRs) were estimated through multivariate Cox proportional hazards modeling.Rates were higher for cohort members in the San Francisco Bay area (HR = 1.22; 95% confidence interval = 1.06-1.40) and Southern Coastal area (1.16; 1.04-1.30) compared with those in the rest of California. The distributions of variables representing socioeconomic status, urbanization, and personal risk factors were consistent with higher risks for cohort members residing in the San Francisco Bay and Southern Coastal areas. Adjustment for these factors, however, did not explain regional differences in incidence, resulting in HRs that remained elevated for these 2 areas.Regional differences in breast cancer incidence in this large, well-defined cohort are not easily explained by known risk factors.

    View details for DOI 10.1097/01.ede.0000134863.45834.50

    View details for Web of Science ID 000224697200014

    View details for PubMedID 15475725

  • Residential proximity to agricultural pesticide use and incidence of breast cancer in the California Teachers Study cohort\ ENVIRONMENTAL RESEARCH Reynolds, P., Hurley, S. E., Goldberg, D. E., Yerabati, S., Gunier, R. B., Hertz, A., Anton-Culver, H., Bernstein, L., Deapen, D., Horn-Ross, P. L., Peel, D., Pinder, R., Ross, R. K., West, D., Wright, W. E., Ziogas, A. 2004; 96 (2): 206-218

    Abstract

    We examined the association between residential proximity to agricultural pesticide use and breast cancer incidence among members of the California Teachers Study cohort, a large study of professional school employees with extensive information on breast cancer risk factors, followed for cancer incidence since 1995. We identified 1552 invasive breast cancer cases, diagnosed between 1996 and 1999, among 114,835 cohort members. We used California Pesticide Use Reporting data to select pesticides for analysis based on use volume, carcinogenic potential, and exposure potential; a Geographic Information System was used to estimate pesticide applications within a half-mile radius of subjects' residences. We applied Cox proportional hazard models to estimate hazard rate ratios (HR) for selected pesticides, adjusting for age, race, and socioeconomic status. We saw no association between residential proximity to recent agricultural pesticide use and invasive breast cancer incidence. HR estimates for the highest compared to the lowest exposure categories for groups of agents were as follows: probable or likely carcinogens (1.07, 95% confidence interval (CI): 0.86-1.32), possible or suggestive carcinogens (1.06, 95% CI: 0.87-1.29), mammary carcinogens (1.15, 95% CI: 0.90-1.48), and endocrine disruptors (1.03, 95% CI: 0.86-1.25). HR estimates for other groups and individual pesticides did not differ from unity, nor was there a trend for any groupings of or individual pesticides examined. Stratifying by menopausal status or family history of breast cancer did not substantially affect our results. Our analyses suggest that breast cancer incidence is not elevated in areas of recent, high agricultural pesticide use in California.

    View details for DOI 10.1016/j.envres.2004.03.001

    View details for Web of Science ID 000223943900011

    View details for PubMedID 15325881

  • Correlates of active and passive smoking in the California Teachers Study cohort JOURNAL OF WOMENS HEALTH Reynolds, P., Hurley, S. E., Hoggatt, K., Anton-Culver, H., Bernstein, L., Deapen, D., Peel, D., Pinder, R., Ross, R. K., West, D., Wright, W., Ziogas, A., Horn-Ross, P. L. 2004; 13 (7): 778-790

    Abstract

    These analyses were designed to describe characteristics associated with active and passive smoking in a large cohort of women in order to identify possible confounders of the relationship between smoking exposures and breast cancer risk.Analyses were based on 1995 data collected from the California Teachers Study (CTS) and were restricted to those with complete and usable tobacco data (n = 128,174). Age-adjusted and race-adjusted odds ratios (OR) were generated by unconditional logistic regression.Compared with never smokers, both current and former smokers experienced menarche at an earlier age. Current and former smokers also were more likely than their never smoking counterparts to be nulliparous. Among parous women, current, but not former smokers were less likely than never smokers to have had their first child at an older age. Similarly, among never smokers, those exposed to household passive smoking experienced menarche at an earlier age, were more likely to be nulliparous, and among parous women, were less likely to have had their first child at an older age than never smokers not exposed to passive smoking. Greater alcohol consumption was strongly associated with both active and passive smoking exposures. Compared with never smokers, current smokers were less likely to take antioxidant supplements, whereas former smokers were more likely to take antioxidant supplements. Among never smokers, antioxidant use did not differ depending on passive smoking exposure. A number of other dietary correlates of active and passive smoking were identified.We identified a number of reproductive and dietary correlates to smoking exposures that underscore the need to adjust for such factors in an analysis of smoking and breast cancer and potentially other disease entities. Furthermore, these findings may suggest potential mechanisms underlying an association between breast cancer and smoking.

    View details for Web of Science ID 000224268000004

    View details for PubMedID 15385072

  • Patterns of alcohol consumption and breast cancer risk in the California Teachers Study cohort CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Horn-Ross, P. L., Canchola, A. J., West, D. W., Stewart, S. L., Bernstein, L., Deapen, D., Pinder, R., Ross, R. K., Anton-Culver, H., Peel, D., Ziogas, A., Reynolds, P., Wright, W. 2004; 13 (3): 405-411

    Abstract

    Alcohol consumption of approximately two drinks or more per day has been associated with elevated breast cancer risk in the California Teachers Study cohort as well as in many other populations. The objective of this analysis is to examine effects of age at drinking and drinking patterns and to identify effect modifiers. Of the 103,460 at-risk cohort members, age <85, who resided in California and completed the baseline alcohol assessment, 1,742 were diagnosed with invasive breast cancer after joining the cohort and before January 2001. Incident breast cancers were identified through the California Cancer Registry and follow-up for death and confirmation of continued California residence used various sources. Multivariate Cox proportional hazards regression models were used to estimate relative risks (RRs). Elevated breast cancer risk was most evident for recent drinking [RR = 1.28, 95% confidence interval (CI): 1.06-1.54 for >/=20 g/day versus nondrinkers], with no clear pattern for consumption during earlier periods of life. This elevation in risk was 32% among postmenopausal women (95% CI: 1.06-1.63) and 21% among pre/perimenopausal women (95% CI: 0.76-1.92). Highest risks associated with heavy alcohol consumption were observed among postmenopausal women with a history of biopsy-diagnosed benign breast disease (RR = 1.97, 95% CI: 1.39-2.79 compared to nondrinkers without benign breast disease) or who had used combination hormone replacement therapy (HRT) (RR = 2.24, 95% CI: 1.59-3.14 compared to nondrinkers who never used HRT). Recent alcohol consumption equivalent to two or more drinks per day increases the risk of invasive breast cancer, with the greatest RRs observed among heavy drinkers who are also postmenopausal and have a history of benign breast disease or who use HRT.

    View details for Web of Science ID 000220081000012

    View details for PubMedID 15006916

  • Active smoking, household passive smoking, and breast cancer: Evidence from the California Teachers Study JOURNAL OF THE NATIONAL CANCER INSTITUTE Reynolds, P., Hurley, S., Goldberg, D. E., Anton-Culver, H., Bernstein, L., Deapen, D., Horn-Ross, P. L., Peel, D., Pinder, R., Ross, R. K., West, D., Wright, W. E., Ziogas, A. 2004; 96 (1): 29-37

    Abstract

    There is great interest in whether exposure to tobacco smoke, a substance containing human carcinogens, may contribute to a woman's risk of developing breast cancer. To date, literature addressing this question has been mixed, and the question has seldom been examined in large prospective study designs.In a 1995 baseline survey, 116 544 members of the California Teachers Study (CTS) cohort, with no previous breast cancer diagnosis and living in the state at initial contact, reported their smoking status. From entry into the cohort through 2000, 2005 study participants were newly diagnosed with invasive breast cancer. We estimated hazard ratios (HRs) for breast cancer associated with several active smoking and household passive smoking variables using Cox proportional hazards models.Irrespective of whether we included passive smokers in the reference category, the incidence of breast cancer among current smokers was higher than that among never smokers (HR = 1.32, 95% confidence interval [CI] = 1.10 to 1.57 relative to all never smokers; HR = 1.25, 95% CI = 1.02 to 1.53 relative to only those never smokers who were unexposed to household passive smoking). Among active smokers, breast cancer risks were statistically significantly increased, compared with all never smokers, among women who started smoking at a younger age, who began smoking at least 5 years before their first full-term pregnancy, or who had longer duration or greater intensity of smoking. Current smoking was associated with increased breast cancer risk relative to all nonsmokers in women without a family history of breast cancer but not among women with such a family history. Breast cancer risks among never smokers reporting household passive smoking exposure were not greater than those among never smokers reporting no such exposure.Our study provides evidence that active smoking may play a role in breast cancer etiology and suggests that further research into the connection is warranted, especially with respect to genetic susceptibilities.

    View details for DOI 10.1093/jnci.djh002

    View details for Web of Science ID 000188253400009

    View details for PubMedID 14709736

  • Comparison of methods for identifying a population- based sample of Filipina women for a health survey ETHNICITY & DISEASE Hoggatt, K. J., Stewart, S. L., Pasick, R., Sabogal, F., Tuason, N., McBride, M. R., Duenas, G. V., Horn-Ross, P. L. 2004; 14 (1): 21-25

    Abstract

    This paper describes and compares 2 random-digit dialing (RDD) methods that have been used to select minority subjects for population-based research. These methods encompass the census-based method, which draws its primary sampling units from census tracts with a high proportion of minority persons, and the registry-based method, which derives its primary sampling units from a population-based cancer registry. Our study targeted Filipinos living in 10 Northern California counties, where they constitute 4% of the total population. Eligible participants (Filipina women, at least aged 20, who spoke 1 of 4 interview languages) were asked to complete a short telephone interview. Both the census and registry methods located Filipino households with comparable efficiency and with a higher yield than would be expected in a non-targeted population survey, such as the Mitofsky-Waksberg RDD method. No systematic pattern of responses was evident that would indicate that either method sampled women who were systematically less acculturated or less likely to use cancer screening tests. Although both methods offer substantial gains in efficiency, their utility is limited by generating samples that tend to over-represent high-density areas. The degree to which these methods are considered viable depends on further refinement to limit, or eliminate, their inherent selection biases without sacrificing their increased efficiency to locate minority populations.

    View details for Web of Science ID 000220239600005

    View details for PubMedID 15002919

  • Validating California teachers study self-reports of recent hospitalization: Comparison with California hospital discharge data AMERICAN JOURNAL OF EPIDEMIOLOGY Marshall, S. F., Deapen, D., Allen, M., Anton-Culver, H., Bernstein, L., Horn-Ross, P. L., Peel, D., Pinder, R., Reynolds, P., Ross, R. K., West, D., Zlogas, A. 2003; 158 (10): 1012-1020

    Abstract

    Determining an accurate method of obtaining complete morbidity data is a long-standing challenge for epidemiologists. The authors compared the accuracy and completeness of existing California hospital discharge data with self-reports of recent hospitalizations and surgeries from participants in the California Teachers Study. Self-reports were collected by questionnaire in 1997 from 91433 female teachers and administrators residing in California. Of the 13430 hospital discharge diagnoses identified for these women, cohort members reported 58%. Self-reporting was highest for neoplasms and musculoskeletal and connective tissue diseases and was most accurate for scheduled admissions, more recent admissions, longer lengths of stay, and less severe disorders. Hospitalizations for mental health and infectious disease were not as well reported. Among the 26383 self-reports-including outpatient surgeries, which are not captured by the hospital discharge database-confirmation was lower, as expected, especially for disorders of the nervous system and sense organs and skin and subcutaneous tissue. Confirmation was highest for childbirth admissions. The hospital discharge database was more specific, but the self-reports were more comprehensive, since many conditions are now treated in outpatient settings. The combination of self-reports and secondary medical records provides more accurate and complete morbidity data than does use of either source alone.

    View details for DOI 10.1093/aie/kwg256

    View details for Web of Science ID 000186544200013

    View details for PubMedID 14607810

  • Lifetime physical activity and breast cancer risk in a multiethnic population: The San Francisco Bay area breast cancer study CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION John, E. M., Horn-Ross, P. L., Koo, J. 2003; 12 (11): 1143-1152

    Abstract

    Considerable epidemiological data have accumulated in support of a lower risk of breast cancer among physically active women. Few studies, however, have examined the relation with lifetime physical activity from all sources, and moderate activity in particular. We conducted a population-based case-control study of breast cancer in Latinas, African Americans, and whites aged 35-79 years to assess the association with lifetime histories of moderate and vigorous physical activity, including recreational activity, walking, bicycling, household and outdoor chores, and occupation. Patients diagnosed with invasive breast cancer between 1995 and 1998 were identified through the cancer registry in the San Francisco Bay area, and a random sample of women without breast cancer was identified through random-digit dialing. A structured questionnaire administered in-person was completed by 403 premenopausal cases and 483 controls and 847 postmenopausal cases and 1065 controls. Summing activities from all sources over an individual's lifetime, we found reduced breast cancer risk in both pre- and postmenopausal women with the highest versus lowest tertile of average lifetime activity (premenopausal: multivariate adjusted odds ratio = 0.74, 95% confidence interval = 0.52-1.05; postmenopausal: odds ratio = 0.81, 95% confidence interval = 0.64-1.02), with similar reductions in the three racial/ethnic groups. In premenopausal women, risk reductions were similar for different types of activities, whereas in postmenopausal women, they were limited to occupational activity. Considering the intensity of activities, risk reductions were similar for moderate and vigorous activities. Because few of the currently known risk factors for breast cancer are modifiable, these results underline the public health importance of promoting physically active lifestyles.

    View details for Web of Science ID 000187001700004

    View details for PubMedID 14652273

  • Phytoestrogen intake and endometrial cancer risk JOURNAL OF THE NATIONAL CANCER INSTITUTE Horn-Ross, P. L., John, E. M., Canchola, A. J., Stewart, S. L., Lee, M. M. 2003; 95 (15): 1158-1164

    Abstract

    The development of endometrial cancer is largely related to prolonged exposure to unopposed estrogens. Phytoestrogens (i.e., weak estrogens found in plant foods) may have antiestrogenic effects. We evaluated the associations between dietary intake of seven specific compounds representing three classes of phytoestrogens (isoflavones, coumestans, and lignans) and the risk of endometrial cancer.In a case-control study from the greater San Francisco Bay Area, we collected dietary information from 500 African American, Latina, and white women aged 35-79 years who were diagnosed with endometrial cancer between 1996 and 1999 and from 470 age- and ethnicity-matched control women identified through random-digit dialing. Unconditional logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).Isoflavone (OR = 0.59, 95% CI = 0.37 to 0.93 for the highest versus lowest quartile of exposure) and lignan (OR = 0.68, 95% CI = 0.44 to 1.1) consumptions were inversely related to the risk of endometrial cancer. These associations were slightly stronger in postmenopausal women (OR = 0.44, 95% CI = 0.26 to 0.77 and OR = 0.57, 95% CI = 0.34 to 0.97 for isoflavones and lignans, respectively). Obese postmenopausal women consuming relatively low amounts of phytoestrogens had the highest risk of endometrial cancer (OR = 6.9, 95% CI = 3.3 to 14.5 compared with non-obese postmenopausal women consuming relatively high amounts of isoflavones); however, the interaction between obesity and phytoestrogen intake was not statistically significant.Some phytoestrogenic compounds, at the levels consumed in the typical American-style diet, are associated with reduced risk of endometrial cancer.

    View details for DOI 10.1093/jnci/djg015

    View details for Web of Science ID 000184710300011

    View details for PubMedID 12902445

  • Recent trends and racial/ethnic differences in the incidence and treatment of ductal carcinoma in situ of the breast in California women CANCER Innos, K., Horn-Ross, P. L. 2003; 97 (4): 1099-1106

    Abstract

    The rapid increase in the incidence of ductal carcinoma in situ (DCIS) of the breast in the U.S. has been associated with the widespread adoption of screening mammography. Little is known regarding the incidence and treatment of DCIS in women of racial/ethnic groups other than white and black. The current investigation examined recent trends and racial/ethnic differences in the incidence and treatment of DCIS in California.All cases of DCIS diagnosed in women age > or = 40 years in California between 1988-1999 were included. Age-adjusted incidence rates for white, black, Hispanic, and Asian-Pacific Islander women were calculated using the 2000 U.S. female population as the standard. The estimated annual percent change (EAPC) in the rates was calculated using least squares regression.The average annual age-adjusted incidence of DCIS (1988-1999) was 45.3 per 100,000 in white women, 35.0 in black women, 30.9 in Asian-Pacific Islander women, and 21.8 in Hispanic women. Although a steady increase in the incidence of DCIS was noted in all racial/ethnic groups over the study period, Asian-Pacific Islander women were found to have experienced the steepest increase (EAPC = 9.1%), particularly in the age group 50-64 years (EAPC = 12.0%). The DCIS incidence was reported to increase with age in white, black, and Hispanic women, but remained fairly constant after the age of 50 years in Asian-Pacific Islanders. The proportion of women with DCIS treated with mastectomy decreased from 53% in 1988 to 32% in 1999. Younger women and Asian-Pacific Islander women reportedly were more likely to undergo mastectomy.Considerable differences by race/ethnicity and age were observed in DCIS incidence and the change in the incidence in California between 1988 and 1999. Further information is needed to determine whether these differences are because of differential utilization of screening mammography or biologic characteristics of DCIS lesions.

    View details for DOI 10.1002/cncr.11104

    View details for Web of Science ID 000180795500025

    View details for PubMedID 12569612

  • Why are thyroid cancer rates so high in southeast Asian women living in the United States? The Bay Area Thyroid Cancer Study CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Haselkorn, T., Stewart, S. L., Horn-Ross, P. L. 2003; 12 (2): 144-150

    Abstract

    The purpose of this study is to understand why thyroid cancer incidence rates are higher among Southeast Asian (SA) women living in the United States than among other United States women. A multiethnic population-based, case-control study of thyroid cancer among women ages 20-74 was conducted in the San Francisco Bay Area. Cases diagnosed between 1992 and 1998 were identified through the area's population-based cancer registry. Controls were identified using random digit dialing and matched to cases on age and ethnicity. Asian women were classified as SA (n = 214) or Northern Asian (n = 196) based on self-reported ethnicity. Relative attributable risks, by age group (<50 and 50+), were calculated to assess what proportion of the difference in incidence rates between these populations could be attributed to the prevalence of specific thyroid cancer risk factors, assuming common relative risks across ethnic groups. Among younger women, a history of goiter or thyroid nodules and lower consumption of isoflavones from soy-based foods account for 66% of the difference in incidence between SA and Northern Asian women. Among older women, these factors, along with recent migration, accounted for 95% of the difference between these groups. When comparing SA with Caucasian women, goiter/nodules and lower consumption of carotenoids explained 67% of the difference in incidence in younger women, whereas goiter/nodules and socioeconomic variables explained 81% of the difference in incidence in older women. A greater prevalence of goiter and thyroid nodules accounts for a substantial portion of the higher thyroid cancer incidence rates among SA women. Dietary patterns also contribute to the rate differences.

    View details for Web of Science ID 000180918800010

    View details for PubMedID 12582024

  • Correlates of vitamin supplement use in the United States: data from the California Teachers Study cohort CANCER CAUSES & CONTROL Hoggatt, K. J., Bernstein, L., Reynolds, P., Anton-Culver, H., Deapen, D., Peel, D., Pinder, R., Ross, R. K., West, D. W., Wright, W., Ziogas, A., Horn-Ross, P. L. 2002; 13 (8): 735-740

    Abstract

    To describe factors associated with vitamin supplement use in a large cohort of adult women.California teachers and administrators (n = 133,479) completed a questionnaire on lifestyle factors and medical history. Specific supplement users regularly used at least one specific vitamin supplement in the past year; multivitamin users regularly used a multivitamin; and multivitamin and specific supplement users took a multivitamin and one or more specific supplements. Associations between supplement use and other variables were quantified using means, cross-tabulations, and age-adjusted prevalence odds ratios.Multivitamin and specific supplement users tended to be older and Caucasian. Compared to non-users, they were also leaner (odds ratio [OR] for BMI > or = 30 kg/m2 = 0.6 for specific supplement users with or without multivitamins, and OR = 0.7 for multivitamin only users), and were less likely to be current smokers (OR for current smoking = 0.8 for multivitamin plus specific supplement users, OR = 0.9 for specific supplement only users, and OR = 0.7 for multivitamin only users). Specific supplement users (with or without multivitamins) were more likely to use cancer screening tests, eat fruits and vegetables, and exercise than were multivitamin only users or non-users.A variety of demographic, dietary, and health-related factors were associated with different categories of supplement use.

    View details for Web of Science ID 000178063700006

    View details for PubMedID 12420952

  • High breast cancer incidence rates among California teachers: results from the California Teachers Study (United States) CANCER CAUSES & CONTROL Bernstein, L., Allen, M., Anton-Culver, H., Deapen, D., Horn-Ross, P. L., Peel, D., Pinder, R., Reynolds, P., Sullivan-Halley, J., West, D., Wright, W., Ziogas, A., Ross, R. K. 2002; 13 (7): 625-635

    Abstract

    [corrected] To determine risk factor profiles and cancer incidence rates among participants in the California Teachers Study (CTS), a study designed to document high breast cancer incidence rates of California teachers and to investigate emergent hypotheses in the etiology of breast and other cancers.The CTS is a prospective study of 133,479 California female teachers and administrators, established in 1995-1996 with members of the California State Teachers Retirement System completing a detailed mailed questionnaire regarding possible risk factors for breast and other cancers. Cancer outcomes were identified by linkage with the California Cancer Registry.CTS participants have a 51% higher age-standardized invasive breast cancer incidence rate and a 67% higher in-situ breast cancer incidence rate than would be expected based on race-specific statewide rates after three years of follow-up. CTS participants also have substantially elevated rates of endometrial cancer (rate ratio, RR = 1.72), ovarian cancer (RR = 1.28), melanoma (RR = 1.59), non-Hodgkin's lymphoma (RR= 1.53), and leukemia (RR = 1.28), but low rates of invasive cervix cancer (RR = 0.53) and lung cancer (RR = 0.66).CTS members have high rates of several major cancers, particularly breast cancer, and low rates of lung and cervix cancer. Although late age at first birth can explain a portion of the observed excess risk of breast cancer in this cohort, the unique risk factor profile of CTS members may account for much of their higher risk of breast and selected other cancers. The CTS offers a rich resource for future studies of cancer risk and of women's health, in general.

    View details for Web of Science ID 000177225300005

    View details for PubMedID 12296510

  • Recent diet and breast cancer risk: the California Teachers Study (USA) CANCER CAUSES & CONTROL Horn-Ross, P. L., Hoggatt, K. J., West, D. W., Krone, M. R., Stewart, S. L., Anton-Culver, H., Bernstein, L., Deapen, D., Peel, D., Pinder, R., Reynolds, P., Ross, R. K., Wright, W., Ziogas, A. 2002; 13 (5): 407-415

    Abstract

    The impact, if any, on breast cancer risk of modifying adult dietary intake is an area of much interest. We take the opportunity to address the relationship between recent adult diet and breast cancer risk during the first two years of follow-up of the large California Teachers Study cohort.Of the 111.526 at-risk cohort members who resided in California and completed a baseline dietary assessment, 711 were diagnosed with invasive breast cancer after joining the cohort and before January 1998. Average daily nutrient intake was computed based on a food-frequency questionnaire assessing usual dietary intake and portion size during the year prior to joining the cohort. Incident breast cancers were identified through the California Cancer Registry and follow-up for death and confirmation of continued California residence utilized a variety of data sources. Cox proportional hazards models were used to calculate relative hazards.The following components of recent dietary intake were not associated with breast cancer risk: energy, fat, fiber, antioxidant vitamins, and phytoestrogens. Only recent average alcohol consumption of 20 or more grams per day (approximately two or more glasses of wine) was associated with increased risk (RR= 1.5, 95% CI: 1.2-2.0 compared to non-drinkers; P(trend) = 0.01 across quintiles).With the exception of alcohol consumption, this study provides no evidence that recent macro- or micronutrient composition of adult diet is likely to have a direct effect on breast cancer risk. Some reduction of alcohol consumption among those consuming more than one drink per day may be beneficial.

    View details for Web of Science ID 000175947900003

    View details for PubMedID 12146845

  • Reproductive and menstrual history and papillary thyroid cancer risk: The San Francisco Bay Area thyroid cancer study CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Sakoda, L. C., Horn-Ross, P. L. 2002; 11 (1): 51-57

    Abstract

    Thyroid cancer rates are three times higher in women than men during the period between puberty and menopause, suggesting that the etiology of thyroid cancer may be related to female sex hormones and reproductive function. However, the results from epidemiological studies have been mixed. To assess this hypothesis, data on menstrual history, pregnancy history, and exogenous hormone use were analyzed from a population-based, case-control study conducted in the San Francisco Bay Area. Of 817 incident thyroid cancer patients (cases), ages 20-74 years, who were diagnosed in 1992-1998 and 793 controls, identified by random-digit dialing and frequency matched to cases on age and race/ethnicity, 608 (74%) cases and 558 (70%) controls were interviewed. Of these cases, 544 were of papillary histology and included in the present analysis. Women who reported onset of menarche before age 12 or after age 14 were at about 50% increased risk for papillary thyroid cancer; however, this effect differed among age- and ethnic-specific subgroups. Among parous women younger than age 45, risk was elevated for several variables measuring recency of pregnancy. Risk was reduced for women who had ever used oral contraceptives [odds ratio (OR), 0.73; 95% confidence interval (CI), 0.52-0.97], but there was no trend with duration of use. Although it remains unclear how sex hormones influence thyroid carcinogenesis, these relationships warrant further investigation.

    View details for Web of Science ID 000173632800009

    View details for PubMedID 11815401

  • Phytoestrogens and thyroid cancer risk: The San Francisco Bay Area thyroid cancer study CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Horn-Ross, P. L., Hoggatt, K. J., Lee, M. M. 2002; 11 (1): 43-49

    Abstract

    Epidemiological and pathological data suggest that thyroid cancer may well be an estrogen-dependent disease. The relationship between thyroid cancer risk and dietary phytoestrogens, which can have both estrogenic and antiestrogenic properties, has not been previously studied. We present data from a multiethnic population-based case-control study of thyroid cancer conducted in the San Francisco Bay Area. Of 817 cases diagnosed between 1995 and 1998 (1992 and 1998 for Asian women), 608 (74%) were interviewed. Of 793 controls identified through random-digit dialing, 558 (70%) were interviewed. Phytoestrogen consumption was assessed via a food-frequency questionnaire and a newly developed nutrient database. The consumption of traditional and nontraditional soy-based foods and alfalfa sprouts were associated with reduced risk of thyroid cancer. Consumption of "western" foods with added soy flour or soy protein did not affect risk. Of the seven specific phytoestrogenic compounds examined, the isoflavones, daidzein and genistein [odds ratio (OR), 0.70; 95% confidence interval (CI), 0.44-1.1; and OR, 0.65, 95% CI, 0.41-1.0, for the highest versus lowest quintile of daidzein and genistein, respectively] and the lignan, secoisolariciresinol (OR, 0.56; 95% CI, 0.35-0.89, for the highest versus lowest quintile) were most strongly associated with risk reduction. Findings were similar for white and Asian women and for pre- and postmenopausal women. Our findings suggest that thyroid cancer prevention via dietary modification of soy and/or phytoestrogen intake in other forms may be possible but warrants further research at this time.

    View details for Web of Science ID 000173632800008

    View details for PubMedID 11815400

  • Iodine and thyroid cancer risk among women in a multiethnic population: The Bay Area thyroid cancer study CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Horn-Ross, P. L., Morris, J. S., Lee, M., West, D. W., Whittemore, A. S., McDougall, I. R., Nowels, K., Stewart, S. L., Spate, V. L., Shiau, A. C., Krone, M. R. 2001; 10 (9): 979-985

    Abstract

    Research on the relationship between iodine exposure and thyroid cancer risk is limited, and the findings are inconclusive. In most studies, fish/shellfish consumption has been used as a proxy measure of iodine exposure. The present study extends this research by quantifying dietary iodine exposure as well as incorporating a biomarker of long-term (1 year) exposure, i.e., from toenail clippings. This study is conducted in a multiethnic population with a wide variation in thyroid cancer incidence rates and substantial diversity in exposure. Women, ages 20-74, residing in the San Francisco Bay Area and diagnosed with thyroid cancer between 1995 and 1998 (1992-1998 for Asian women) were compared with women selected from the general population via random digit dialing. Interviews were conducted in six languages with 608 cases and 558 controls. The established risk factors for thyroid cancer were found to increase risk in this population: radiation to the head/neck [odds ratio (OR), 2.3; 95% confidence interval (CI), 0.97-5.5]; history of goiter/nodules (OR, 3.7; 95% CI, 2.5-5.6); and a family history of proliferative thyroid disease (OR, 2.5; 95% CI, 1.6-3.8). Contrary to our hypothesis, increased dietary iodine, most likely related to the use of multivitamin pills, was associated with a reduced risk of papillary thyroid cancer. This risk reduction was observed in "low-risk" women (i.e., women without any of the three established risk factors noted above; OR, 0.53; 95% CI, 0.33-0.85) but not in "high-risk" women, among whom a slight elevation in risk was seen (OR, 1.4; 95% CI, 0.56-3.4). However, no association with risk was observed in either group when the biomarker of exposure was evaluated. In addition, no ethnic differences in risk were observed. The authors conclude that iodine exposure appears to have, at most, a weak effect on the risk of papillary thyroid cancer.

    View details for Web of Science ID 000170899000011

    View details for PubMedID 11535551

  • Phytoestrogen consumption and breast cancer risk in a multiethnic population - The Bay Area Breast Cancer Study AMERICAN JOURNAL OF EPIDEMIOLOGY Horn-Ross, P. L., John, E. M., Lee, M., Stewart, S. L., Koo, J., Sakoda, L. C., Shiau, A. G., Goldstein, J., Davis, P., Perez-Stable, E. J. 2001; 154 (5): 434-441

    Abstract

    Research on the relation between phytoestrogens and breast cancer risk has been limited in scope. Most epidemiologic studies have involved Asian women and have examined the effects of traditional soy foods (e.g., tofu), soy protein, or urinary excretion of phytoestrogens. The present study extends this research by examining the effects of a spectrum of phytoestrogenic compounds on breast cancer risk in non-Asian US women. African-American, Latina, and White women aged 35-79 years, who were diagnosed with breast cancer between 1995 and 1998, were compared with women selected from the general population via random digit dialing. Interviews were conducted with 1,326 cases and 1,657 controls. Usual intake of specific phytoestrogenic compounds was assessed via a food frequency questionnaire and a newly developed nutrient database. Phytoestrogen intake was not associated with breast cancer risk (odds ratio = 1.0, 95% confidence interval: 0.80, 1.3 for the highest vs. lowest quartile). Results were similar for pre- and postmenopausal women, for women in each ethnic group, and for all seven phytoestrogenic compounds studied. Phytoestrogens appear to have little effect on breast cancer risk at the levels commonly consumed by non-Asian US women: an average intake equivalent to less than one serving of tofu per week.

    View details for Web of Science ID 000171019700007

    View details for PubMedID 11532785

  • Assessing phytoestrogen exposure via a food-frequency questionnaire CANCER CAUSES & CONTROL Horn-Ross, P. L. 2001; 12 (5): 477-478

    View details for Web of Science ID 000170052000010

    View details for PubMedID 11545462

  • Assessing phytoestrogen exposure in epidemiologic studies: development of a database (United States) CANCER CAUSES & CONTROL Horn-Ross, P. L., Barnes, S., Lee, M., Coward, L., Mandel, J. E., Koo, J., John, E. M., Smith, M. 2000; 11 (4): 289-298

    Abstract

    Phytoestrogens (weak estrogens found in plants or derived from plant precursors by human metabolism) have been hypothesized to reduce the risk of a number of cancers. However, epidemiologic studies addressing this issue are hampered by the lack of a comprehensive phytoestrogen database for quantifying exposure. The purpose of this research was to develop such a database for use with food-frequency questionnaires in large epidemiologic studies.The database is based on consumption patterns derived from semistructured interviews with 118 African-American, Latina, and white women residing in California's San Francisco Bay Area. HPLC-mass spectrometry was used to determine the content of seven specific phytoestrogenic compounds (i.e. the isoflavones: genistein, daidzein, biochanin A, and formononetin; the coumestan: coumestrol; and the plant lignans: matairesinol and secoisolariciresinol) in each of 112 food items/groups.Traditional soy-based foods were found to contain high levels of genistein and daidzein, as expected, as well as substantial amounts of coumestrol. A wide variety of "hidden" sources of soy (that is, soy protein isolate, soy concentrate, or soy flour added to foods) was observed. Several other foods (such as various types of sprouts and dried fruits, garbanzo beans, asparagus, garlic, and licorice) were also found to be substantial contributors of one or more of the phytoestrogens analyzed.Databases, such as the one described here, are important in assessing the relationship between phytoestrogen exposure and cancer risk in epidemiologic studies. Agencies, such as the United States Department of Agriculture (USDA), that routinely provide data on food composition, on which epidemiologic investigations into dietary health effects are based, should consider instituting programs for the analysis of phytochemicals, including the phytoestrogens.

    View details for Web of Science ID 000087586700001

    View details for PubMedID 10843440

  • Sources of phytoestrogen exposure among non-Asian women in California, USA CANCER CAUSES & CONTROL Horn-Ross, P. L., Lee, M., John, E. M., Koo, J. 2000; 11 (4): 299-302

    Abstract

    We recently described the development of a comprehensive database for assessing phytoestrogen exposure in epidemiologic studies. This paper describes the first application of this database and the primary sources of phytoestrogen consumption in non-Asian women.Four hundred and forty-seven randomly selected African-American, Latina, and white women, ages 50-79 years, residing in California's San Francisco Bay Area and participating as controls in an ongoing population-based case-control study of breast cancer, were included in the present analysis. Average daily consumption of each of seven phytoestrogenic compounds was determined for each woman by combining the values from the new database with food consumption reported on a food-frequency questionnaire.Phytoestrogens in the non-Asian Bay Area diet appear to come primarily from: (1) traditional soy-based foods (e.g. tofu and soy milk); (2) "hidden" sources of soy (e.g. foods containing added soy protein isolate, soy concentrate, or soy flour, e.g. many brands of doughnuts and white bread); and (3) a variety of foods which contain only low to moderate amounts of phytoestrogens per 100 grams but which are frequently consumed (e.g. coffee and orange juice).In the absence of a comprehensive assessment of various phytoestrogens in a wide variety of foods, epidemiologic studies could suffer from the effects of uncontrolled confounding by unmeasured sources of phytoestrogen exposure potentially leading to biased estimates of effect and misinterpretation of findings.

    View details for Web of Science ID 000087586700002

    View details for PubMedID 10843441

  • Menstrual and reproductive factors for salivary gland cancer risk in women EPIDEMIOLOGY Horn-Ross, P. L., Morrow, M., Ljung, B. M. 1999; 10 (5): 528-530

    Abstract

    Several observations suggest that salivary gland cancer may be, in part, a hormonally dependent disease. We examined associations between hormonally mediated life events and salivary gland cancer risk in a population-based case-control study. Of 76 women diagnosed between 1989 and 1993, 63 (83%) were interviewed. Of 111 population controls, 83 (75%) were interviewed. Early menarche (OR = 4.1, 95% CI = 1.4-12.1) and nulliparity (OR = 2.6, 95% CI = 1.0-6.7) were associated with increased risk whereas late age at first full-term pregnancy (OR = 0.19, 95% CI = 0.3-1.2) and longer duration of oral contraceptive use (OR = 0.31, 95% CI = 0.10-1.0) were associated with diminished risk. These findings are consistent with a hormonal component in salivary gland cancer risk.

    View details for Web of Science ID 000082075800011

    View details for PubMedID 10468426

  • Comparison of methods for classifying Hispanic ethnicity in a population-based cancer registry AMERICAN JOURNAL OF EPIDEMIOLOGY Stewart, S. L., Swallen, K. C., Glaser, S. L., Horn-Ross, P. L., West, D. W. 1999; 149 (11): 1063-1071

    Abstract

    The accuracy of ethnic classification can substantially affect ethnic-specific cancer statistics. In the Greater Bay Area Cancer Registry, which is part of the Surveillance, Epidemiology, and End Results (SEER) Program and of the statewide California Cancer Registry, Hispanic ethnicity is determined by medical record review and by matching to surname lists. This study compared these classification methods with self-report. Ethnic self-identification was obtained by surveying 1,154 area residents aged 20-89 years who were diagnosed with cancer in 1990 and were reported to the registry as being Hispanic or White non-Hispanic. Predictive value positive, sensitivity, and relative bias were used to assess the accuracy of Hispanic classification by medical record and surname. Among those persons classified as Hispanic by either or both of these sources, only two-thirds agreed (predictive value positive = 66%), and many self-identified Hispanics were classified incorrectly (sensitivity = 68%). Classification based on either medical record or surname alone had a lower sensitivity (59% and 61%, respectively) but a higher predictive value positive (77% and 70%, respectively). Ethnic classification by medical record alone resulted in an underestimate of Hispanic cancer cases and incidence rates. Bias was reduced when medical records and surnames were used together to classify cancer cases as Hispanic.

    View details for Web of Science ID 000080524100012

    View details for PubMedID 10355383

  • Social class, race/ethnicity, and incidence of breast, cervix, colon, lung, and prostate cancer among Asian, black, Hispanic, and white residents of the San Francisco Bay Area, 1988-92 (United States) CANCER CAUSES & CONTROL Krieger, N., Quesenberry, C., Peng, T., Horn-Ross, P., Stewart, S., Brown, S., Swallen, K., Guillermo, T., Suh, D., Alvarez-Martinez, L., Ward, F. 1999; 10 (6): 525-537

    Abstract

    To date only eight US studies have simultaneously examined cancer incidence in relation to social class and race/ethnicity; all but one included only black and white Americans. To address gaps in knowledge we thus investigated socioeconomic gradients in cancer incidence among four mutually exclusive US racial/ethnic groups-- Asian and Pacific Islander, black, Hispanic, and white-- for five major cancer sites: breast, cervix, colon, lung, and prostate cancer.We generated age-adjusted cancer incidence rates stratified by socioeconomic position using: (a) geocoded cancer registry records, (b) census population counts, and (c) 1990 census block-group socioeconomic measures. Cases (n = 70,899) were diagnosed between 1988 and 1992 and lived in seven counties located in California's San Francisco Bay Area.Incidence rates varied as much if not more by socioeconomic position than by race/ethnicity, and for each site the magnitude - and in some cases direction - of the socioeconomic gradient differed by race/ethnicity and, where applicable, by gender. Breast cancer incidence increased with affluence only among Hispanic women. Incidence of cervical cancer increased with socioeconomic deprivation among all four racial/ethnic groups, with trends strongest among white women. Lung cancer incidence increased with socioeconomic deprivation among all but Hispanics, for whom incidence increased with affluence. Colon and prostate cancer incidence were inconsistently associated with socioeconomic position.These complex patterns defy easy generalization and illustrate why US cancer data should be stratified by socioeconomic position, along with race/ethnicity and gender, so as to improve cancer surveillance, research, and control.

    View details for Web of Science ID 000083692900006

    View details for PubMedID 10616822

  • Soy intake and risk of breast cancer in Asians and Asian Americans AMERICAN JOURNAL OF CLINICAL NUTRITION Wu, A. H., Ziegler, R. G., Nomura, A. M., West, D. W., Kolonel, L. N., Horn-Ross, P. L., HOOVER, R. N., Pike, M. C. 1998; 68 (6): 1437S-1443S

    Abstract

    Evidence from case-control studies suggests, although not entirely consistently, that soy intake may protect against breast cancer. The designs and findings of studies conducted in Asian women living in Japan, Singapore, China, and the United States are reviewed. Because of the considerably higher intake of soy by native Asians than by Asian Americans living in California and Hawaii, these studies investigated different segments of the dose-response relation between soy intake and breast cancer risk. Data are not sufficient to determine the amount or frequency of soy intake effective in protecting against breast cancer. Of concern is that soy intake may be homogeneously high in Asia, making it difficult to identify differences in breast cancer risk between high and moderate daily consumers. In studies conducted in Asian Americans, it is difficult to be certain that soy intake is not a marker of other factors related to Western lifestyle that are causally associated with risk of breast cancer. Additional studies assessing the role of soy and breast cancer are needed. These studies should assess intake of all food sources of soy, considering portion size as well as other dietary and nondietary factors that may confound the soy-breast cancer association. A better understanding of the mechanisms whereby soy intake may influence the risk of breast cancer is also needed. Dietary intervention studies with soy will provide information on the acute effects of soy on endogenous hormone concentrations. Cross-sectional and longitudinal studies are necessary to investigate the longer-term relations between hormone concentrations and soy intake in women.

    View details for Web of Science ID 000077392300020

    View details for PubMedID 9848513

  • Adjustment of cancer incidence rates for ethnic misclassification BIOMETRICS Stewart, S. L., Swallen, K. C., Glaser, S. L., Horn-Ross, P. L., West, D. W. 1998; 54 (2): 774-781

    Abstract

    Although ethnic population counts measured by the United States Census are based on self-identification, the same is not necessarily true of cases reported to cancer registries. The use of different ethnic classification methods for numerators and denominators may therefore lead to biased estimates of cancer incidence rates. The extent of such misclassification may be assessed by conducting an ethnicity survey of cancer patients and estimating the proportion misclassified using double sampling models that account for sample stratification. For two ethnic categories, logistic regression may be used to model self-identified ethnicity as a function of demographic variables and the fallible classification method. Incidence rates then may be adjusted for misclassification using regression results to estimate the number of cancer cases of a given age, sex, and site in each self-identified ethnic group. An example is given using this method to estimate ethnic misclassification of San Francisco Bay area Hispanic cancer patients diagnosed in 1990. Results suggest that the number of cancer cases reported as Hispanic is an underestimate of the number of cases self-identified as Hispanic, resulting in an underestimate of Hispanic cancer rates.

    View details for Web of Science ID 000074161600033

    View details for PubMedID 9629656

  • Absence of Epstein-Barr virus EBER-1 transcripts in an epidemiologically diverse group of breast cancers INTERNATIONAL JOURNAL OF CANCER Glaser, S. L., Ambinder, R. F., DiGiuseppe, J. A., Horn-Ross, P. L., Hsu, J. L. 1998; 75 (4): 555-558

    Abstract

    Epstein-Barr virus (EBV), a ubiquitous herpesvirus associated with certain lymphomas and carcinomas, has been identified within the malignant cells of a small proportion of breast tumors. As breast cancer is a very common malignancy in women, a pathogenetic role of EBV for even a subgroup of patients could have important implications for etiology and prevention. Therefore, we attempted to confirm the EBV-breast cancer association by exploring it in a representative case series stratified by characteristics that modify breast cancer risk. We studied a sample of 97 female and 28 male patients identified from a US population-based cancer registry. Patients were selected randomly within age, sex, ethnicity and tumor estrogen-receptor status groups. With their archived tumor tissues, we examined EBV presence using in situ hybridization for the EBER-1 transcript. In the 107 technically adequate specimens, we did not detect this viral transcript in any tumors, including one from a woman who also had an EBER-positive nasopharyngeal carcinoma. Our uniformly negative findings are extremely unlikely to have occurred by chance and cannot be attributed to selective sampling, as our study group included persons at diverse risk for breast cancer. We conclude that the EBV EBER-1 transcript is not commonly expressed in breast cancer, based on a broadly representative case series, though we cannot exclude an association of EBV within a particular population subgroup.

    View details for Web of Science ID 000071797400010

    View details for PubMedID 9466655

  • Diet and the risk of salivary gland cancer AMERICAN JOURNAL OF EPIDEMIOLOGY HORNROSS, P. L., Morrow, M., Ljung, B. M. 1997; 146 (2): 171-176

    Abstract

    Cancer of the major salivary glands is relatively rare, and little is known about its etiology. The only established risk factors are radiation exposure and a prior cancer. The role of diet in the development of salivary gland tumors has not been addressed previously. The results from a population-based case-control study conducted in the greater San Francisco-Monterey Bay area examining the association between dietary intake and salivary gland cancer risk are presented. Of 199 cases diagnosed with salivary gland tumors between 1989 and 1993, 150 (75%) were interviewed. Nine cases were subsequently excluded based on review of pathology specimens. Of 271 controls identified through random-digit dialing and the Health Care Finance Administration files, 191 (70%) were interviewed. Eight cases and seven controls who over- or underreported dietary intake were excluded from analysis. Vitamin C intake of > 200 mg/day compared with < or = 100 mg/day was associated with a 60% decrease in salivary gland cancer risk (odds ratio (OR) = 0.40, 95% confidence interval (CI) 0.22-0.70). Inverse associations observed for carotene, vitamin E, and fiber from fruits and vegetables were diminished when adjusted for vitamin C intake. Fiber from been sources was associated with a 51% decrease in risk after adjusting for vitamin C intake (OR = 0.49, 95% CI 0.26-0.92 for > 1.4 g/day compared with < or = 0.4 g/day). Cholesterol intake was associated with elevated risk (OR = 1.67, 95% CI 1.2-2.4 for a 10% increase in calories from cholesterol). These findings suggest that preventive strategies developed for common chronic diseases, such as increased consumption of fruits and vegetables and limiting foods high in cholesterol, also may be effective in preventing these rare tumors.

    View details for Web of Science ID A1997XL76400008

    View details for PubMedID 9230779

  • Environmental factors and the risk of salivary gland cancer EPIDEMIOLOGY HORNROSS, P. L., Ljung, B. M., Morrow, M. 1997; 8 (4): 414-419

    Abstract

    Cancer of the major salivary glands is rare, and little is known about its etiology. We conducted a population-based case-control study to elucidate the risk factors for these tumors. Of 199 cases diagnosed with salivary gland tumors between 1989 and 1993, 150 (75%) were interviewed. We subsequently excluded nine cases based on review of pathology specimens. We identified 271 controls through random-digit dialing and the Health Care Finance Administration files; 191 (70%) were interviewed. Therapeutic medical radiation treatment to the head or neck [odds ratio (OR) = 2.6; 95% confidence interval (CI) = 0.84-8.1], full mouth dental x-rays (OR = 1.6; 95% CI = 1.0-2.7), and ultraviolet light treatment to the head or neck (OR = 1.9; 95% CI = 0.89-4.3) were associated with increased risk. These elevations in risk were largely limited to those exposed before 1955, when the exposure dose was substantially higher. Occupational exposure to radiation/radioactive materials (OR = 2.4; 95% CI = 1.0-5.4) and nickel compounds/alloys (OR = 6.0; 95% CI = 1.6-22.0), as well as employment in the rubber industry (OR = 7.0; 95% CI = 0.80-60.3), increased risk. In men, current smoking (OR = 2.1; 95% CI = 0.98-4.7) and heavy alcohol consumption (OR = 2.5; 95% CI = 1.1-5.7) were associated with risk, but these factors were not strongly related to salivary gland cancer in women.

    View details for Web of Science ID A1997XG00500015

    View details for PubMedID 9209856

  • Urinary phytoestrogen levels in young women from a multiethnic population CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION HORNROSS, P. L., Barnes, S., KIRK, M., Coward, L., Parsonnet, J., Hiatt, R. A. 1997; 6 (5): 339-345

    Abstract

    Phytoestrogens include several classes of chemical compounds (i.e., isoflavones, coumestans, and lignans) which are structurally similar to endogenous estrogens. In biological systems, they have both estrogenic and antiestrogenic effects and may reduce the risk of developing certain types of hormonally related diseases. However, little information is available on population differences in exposure to phytoestrogens. To examine racial/ethnic differences in urinary phytoestrogen levels, 50 young women (ages 20-40 years) were randomly selected from participants in a previous epidemiological study in which 24-h urine specimens and a dietary assessment were obtained. Subjects were members of the Kaiser Permanente Medical Care Program of northern California. Selection was stratified on race/ethnicity. Urinary levels of seven phytoestrogens were measured using high-performance liquid chromatography-mass spectrometry. Substantial variation in phytoestrogen levels was observed and racial/ethnic differences are described. The highest levels of coumestrol and the lignans were observed in white women and the lowest levels in Latina and African American women. Genistein levels, however, were highest in Latina women; other isoflavone levels did not differ significantly by race/ethnicity.

    View details for Web of Science ID A1997WZ60300008

    View details for PubMedID 9149894

  • Tofu and risk of breast cancer in Asian-Americans CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION Wu, A. H., Ziegler, R. G., HORNROSS, P. L., Nomura, A. M., West, D. W., Kolonel, L. N., ROSENTHAL, J. F., HOOVER, R. N., Pike, M. C. 1996; 5 (11): 901-906

    Abstract

    Breast cancer rates among Asian-Americans are lower than those of US whites but considerably higher than rates prevailing in Asia. It is suspected that migration to the US brings about a change in endocrine function among Asian women, although reasons for this change remain obscure. The high intake of soy in Asia and its reduced intake among Asian-Americans has been suggested to partly explain the increase of breast cancer rates in Asian-Americans. We conducted a population-based case-control study of breast cancer among Chinese-, Japanese-, and Filipino-American women in Los Angeles County MSA, San Francisco Oakland MSA, and Oahu, Hawaii. Using a common questionnaire which assessed frequency of intake of some 90 food items, 597 Asian-American women (70% of those eligible) diagnosed with incident, primary breast cancer during 1983-1987 and 966 population-based controls (75% of those eligible) were interviewed. Controls were matched to cases on age, ethnicity, and area of residence. This analysis compares usual adult intake of soy (estimated primarily from tofu intake) among breast cancer cases and control women. After adjustment for age, ethnicity and study area, intake of tofu was more than twice as high among Asian-American women born in Asia (62 times per year) compared to those born in the US (30 times per year). Among migrants, intake of tofu decreased with years of residence in the US. Risk of breast cancer decreased with increasing frequency of intake of tofu after adjustment for age, study area, ethnicity, and migration history; the adjusted OR associated with each additional serving per week was 0.85 (95% CI = 0.74-0.99). The protective effect of high tofu intake was observed in pre- and postmenopausal women. This association remained after adjustment for selected dietary factors and menstrual and reproductive factors. However, this study was not designed specifically to investigate the role of soy intake and our assessment of soy intake may be incomplete. We cannot discount the possibility that soy intake is a marker of other protective aspects of Asian diet and/or Asian lifestyle.

    View details for Web of Science ID A1996VR59600008

    View details for PubMedID 8922298

  • Relative weight, weight change, height, and breast cancer risk in Asian-American women JOURNAL OF THE NATIONAL CANCER INSTITUTE Ziegler, R. G., HOOVER, R. N., Nomura, A. M., West, D. W., Wu, A. H., Pike, M. C., Lake, A. J., HORNROSS, P. L., Kolonel, L. N., Siiteri, P. K., Fraumeni, J. F. 1996; 88 (10): 650-660

    Abstract

    Breast cancer incidence rates have historically been four to seven times higher in the United States than in China or Japan, although the reasons remain elusive. When Chinese, Japanese, or Filipino women migrate to the United States, their breast cancer risk rises over several generations and reaches that for white women in the United States, indicating that modifiable exposures are involved. In a previous report on this case-control study of breast cancer in Asian-American women, designed to take advantage of their diversity in risk and lifestyle, we demonstrated a sixfold gradient in risk by migration history, comparable to the international differences in breast cancer incidence rates.In this analysis, we have examined the roles of adult height, adiposity, and weight change in breast cancer etiology.A population-based, case-control study of breast cancer was conducted among women of Chinese, Japanese, and Filipino ethnicities, aged 20-55 years, living in San Francisco-Oakland (CA), Los Angeles (CA), and Oahu (HI) during the period from April 1, 1983, through June 30, 1987. We successfully interviewed 597 (70%) of 852 eligible case subjects and 966 (75%) of 1287 eligible control subjects from August 1985 through February 1989. Subjects were asked about current height, usual adult weight, and usual weight in each decade of life, excluding the most recent 3 years and any periods of pregnancy.Height, recent adiposity (weight in the current decade of life/height 1.5), and recent weight change (between the current and preceding decades of life) were strong predictors of breast cancer risk after adjustment was made for accepted breast cancer risk factors. Risk doubled (relative risk [RR] = 2.01; 95% confidence interval [CI] = 1.16-3.49) over the 7-inch (17.8-cm) range in height (two-sided P for trend = .003), with comparable effects in both premenopausal and postmenopausal women. Except for reduced risk in the heavy, younger women (weight/height 1.5 > 29 kg/m 1.5 and < 40 years old), risk was positively associated with usual adult adiposity. Trends in risk became more striking as adiposity in each succeeding decade of adult life was considered. Women in their 50s and in the top quintile for their age group had twice the breast cancer risk (RR = 2.13; 95% CI = 1.17-3.87) of women in the bottom quintile (two-sided P for trend = .004). Women in their 50s, above the median adiposity for their age group, and with a recent gain of more than 10 pounds had three times the risk (RR = 3.01; 95% CI = 1.45-6.25) of women below the median adiposity and with no recent weight change. Recent weight loss was consistently associated with reduced risk (RRs of approximately 0.7) relative to no recent weight change.Adult adiposity, weight change, and height are critical determinants of breast cancer risk. Increased adiposity and weight gain in the decade preceding diagnosis are especially influential, suggesting that excess weight may function as a late stage promoter.Weight maintenance and/or reduction as an adult, possibly accompanied by specific changes in diet and physical activity, may have a significant and rapid impact on breast cancer risk.

    View details for Web of Science ID A1996UK18600010

    View details for PubMedID 8627641

  • Menstrual and reproductive factors and risk of breast cancer in Asian-Americans BRITISH JOURNAL OF CANCER Wu, A. H., Ziegler, R. G., Pike, M. C., Nomura, A. M., West, D. W., Kolonel, L. N., HORNROSS, P. L., ROSENTHAL, J. F., HOOVER, R. N. 1996; 73 (5): 680-686

    Abstract

    We conducted a population-based case-control study of breast cancer among Chinese-, Japanese- and Filipino-American women in Los Angeles County Metropolitan Statistical Area (MSA), San Francisco-Oakland MSA and Oahu, Hawaii. One objective of the study was to quantify breast cancer risks in relation to menstrual and reproductive histories in migrant and US-born Asian-Americans and to establish whether the gradient of risk in Asian-Americans can be explained by these factors. Using a common study design and questionnaire in the three study areas, we successfully conducted in-person interviews with 597 Asian-American women diagnosed with incident, primary breast cancer during the period 1983-87 (70% of those eligible) and 966 population-based controls (75% of those eligible). Controls were matched to cases on age, ethnicity and area of residence. In the present analysis, which included 492 cases and 768 controls, we observed a statistically non-significant 4% reduction in risk of breast cancer with each year delay in onset of menstruation. Independent of age at menarche risk of breast cancer was lower (odds ratio; OR=0.77) among women with menstrual cycles greater than 29 days. Parous Asian-American women showed a significantly lower risk of breast cancer then nulliparous women (OR=0.54). An increasing number of livebirths and a decreasing age at first livebirth were both associated with a lower risk of breast cancer, although the effect of number of livebirths was no longer significant after adjustment for age at first livebirth. Women with a pregnancy (spontaneous or induced abortions) but no livebirth had a statistically non-significant increased risk (OR=1.84), but there was no evidence that one type of abortion was particularly harmful. A positive history of breastfeeding was associated with non-significantly lower risk of breast cancer (OR=.78). There are several notable differences in the menstrual and reproductive factors between Asian-Americans in this study and published data on US whites. US-born Asian Americans had an average age at menarche of 12.12 years-no older than has been found in comparable studies of US whites, but 1.4 years earlier than Asian women who migrated to the US. Asian-American women, particularly those born in the US and those who migrated before age 36, also had a later age at first birth and fewer livebirths than US whites. A slightly higher proportion of Asian-American women breastfed, compared with US whites. The duration of breastfeeding was similar in US-born Asians and US whites, but was longer in Asian migrants, especially those who migrated at a later age. Menstrual and reproductive factors in Asian-American women are consistent with their breast cancer rates being at least as high as in US whites, and they are. However, the effects of these menstrual and reproductive factors were small and the ORs for migration variables changed only slightly after adjustment for these menstrual and reproductive factors. These results suggest that the lower rates of breast cancer in Asians must be largely as a result of other environmental/lifestyle factors.

    View details for Web of Science ID A1996TV82700022

    View details for PubMedID 8605107

  • PHYTOESTROGENS, BODY-COMPOSITION, AND BREAST-CANCER CANCER CAUSES & CONTROL HORNROSS, P. L. 1995; 6 (6): 567-573

    Abstract

    To the extent that diet is involved in the etiology of breast cancer, its effect may be mediated, in part, through hormonal mechanisms. It has been suggested that the consumption of phytoestrogens is related inversely to breast cancer risk. Phytoestrogens are weak estrogens of plant derivation that may have antiestrogenic effects through competitively binding to estrogen receptors, thus diminishing the binding of stronger endogenous estrogens. This paper advances the hypothesis that, through this mechanism, dietary phytoestrogens may attenuate the adverse consequences of obesity on the development of postmenopausal breast cancer. Such an association might partly explain the low breast cancer rates observed among postmenopausal Hispanic women despite their greater adiposity, an important breast cancer risk factor. This hypothesis would lead us to expect that obesity increases the risk of postmenopausal breast cancer in women consuming small quantities of phytoestrogens but does not increase risk in women consuming larger quantities. If the hypothesis is confirmed, such as association could have important implications for reducing breast cancer risk through diet, using naturally occurring substances, particularly in women for whom postmenopausal obesity is an important health concern.

    View details for Web of Science ID A1995TG14700014

    View details for PubMedID 8580306

  • MIGRATION PATTERNS AND BREAST-CANCER RISK IN ASIAN-AMERICAN WOMEN JOURNAL OF THE NATIONAL CANCER INSTITUTE Ziegler, R. G., HOOVER, R. N., Pike, M. C., Hildesheim, A., Nomura, A. M., West, D. W., WUWILLIAMS, A. H., Kolonel, L. N., HORNROSS, P. L., ROSENTHAL, J. F., HYER, M. B. 1993; 85 (22): 1819-1827

    Abstract

    Breast cancer incidence rates have historically been 4-7 times higher in the United States than in China or Japan, although the reasons remain elusive. When Chinese, Japanese, or Filipino women migrate to the United States, breast cancer risk rises over several generations and approaches that among U.S. Whites.Our objective was to quantify breast cancer risks associated with the various migration patterns of Asian-American women.A population-based, case-control study of breast cancer among women of Chinese, Japanese, and Filipino ethnicities, aged 20-55 years, was conducted during 1983-1987 in San Francisco-Oakland, California, Los Angeles, California, and Oahu, Hawaii. We successfully interviewed 597 case subjects (70% of those eligible) and 966 control subjects (75%).A sixfold gradient in breast cancer risk by migration patterns was observed. Asian-American women born in the West had a breast cancer risk 60% higher than Asian-American women born in the East. Among those born in the West, risk was determined by whether their grandparents, especially grandmothers, were born in the East or the West. Asian-American women with three or four grandparents born in the West had a risk 50% higher than those with all grandparents born in the East. Among the Asian-American women born in the East, breast cancer risk was determined by whether their communities prior to migration were rural or urban and by the number of years subsequently lived in the West. Migrants from urban areas had a risk 30% higher than migrants from rural areas. Migrants who had lived in the West for a decade or longer had a risk 80% higher than more recent migrants. Risk was unrelated to age at migration for women migrating at ages less than 36 years. Ethnic-specific incidence rates of breast cancer in the migrating generation were clearly elevated above those in the countries of origin, while rates in Asian-Americans born in the West approximated the U.S. White rate.Exposure to Western lifestyles had a substantial impact on breast cancer risk in Asian migrants to the United States during their lifetime. There was no direct evidence of an especially susceptible period, during either menarche or early reproductive life.Because heterogeneity in breast cancer risk in these ethnic populations is similar to that in international comparisons and because analytic epidemiologic studies offer the opportunity to disentangle correlated exposures, this study should provide new insights into the etiology of breast cancer.

    View details for Web of Science ID A1993MG53000011

    View details for PubMedID 8230262

  • BREAST-CANCER AMONG BLACK-AND-WHITE WOMEN IN THE 1980S - CHANGING PATTERNS IN THE UNITED-STATES BY RACE, AGE, AND EXTENT OF DISEASE CANCER Swanson, G. M., Ragheb, N. E., Lin, C. S., Hankey, B. F., Miller, B., HORNROSS, P., White, E., Liff, J. M., Harlan, L. C., MCWHORTER, W. P., Mullan, P. B., Key, C. R. 1993; 72 (3): 788-798

    Abstract

    This national study of breast cancer incidence and mortality was conducted to determine whether patterns of change differ for black and white women, to evaluate patterns by extent of disease, and to determine whether recent patterns of breast cancer are consistent with results that one would expect due to increases in use of screening examinations by women.The study included 104,351 cases of in situ or invasive breast cancer diagnosed between 1983 and 1989 among women from the nine geographic areas participating in the National Cancer Institute Surveillance, Epidemiology, and End Results program. Breast cancer incidence patterns were examined by extent of disease for black and white women and by age at diagnosis.Significant increases occurred in the incidence of all early-stage breast cancers. Concomitantly, significant decreases occurred in the incidence of the most advanced-stage breast cancers. Although both white and black women experienced significant increases in early-stage breast cancer, black women have substantially lower rates of the least extensive breast cancers.These results strongly suggest that a major explanation for the increase in breast cancer incidence in the 1980s may well be the increased prevalence of breast cancer screening among women in the United States. They also suggest a consistent benefit of screening across all age groups from 40 to 49 years through 70 years and older.

    View details for Web of Science ID A1993LP72000024

    View details for PubMedID 8334632

  • BREAST-CANCER - MAGNITUDE OF THE PROBLEM AND DESCRIPTIVE EPIDEMIOLOGY - INTRODUCTION EPIDEMIOLOGIC REVIEWS Kelsey, J. L., HORNROSS, P. L. 1993; 15 (1): 7-16

    Abstract

    Breast cancer is the most common cancer among women in the United States. Knowledge of the descriptive epidemiology of breast cancer is useful both in suggesting etiologic hypotheses and, if preventive measures can be identified, in delineating high-risk groups to be targeted for preventive efforts. Demographic risk factors include increasing age (in Western countries), being white for breast cancer diagnosed at age 45 years or more, being black for breast cancer diagnosed at less than 40 years of age, high socioeconomic status, having never married, being of the Jewish faith, urban residence, and residence in the northern (as compared with the southern) United States. Incidence rates are generally highest in North American and Northern European countries, intermediate in Southern and Eastern European and South American countries, and lowest in Asia and Africa. The most notable characteristic of the descriptive epidemiology of breast cancer in recent years is perhaps the rapidly increasing incidence rates in developing countries. Identification of specific reasons for these increasing rates would contribute substantially to our understanding of the epidemiology of breast cancer.

    View details for Web of Science ID A1993LV35100003

    View details for PubMedID 8405214

  • MULTIPLE PRIMARY CANCERS INVOLVING THE BREAST EPIDEMIOLOGIC REVIEWS HORNROSS, P. L. 1993; 15 (1): 169-176

    View details for Web of Science ID A1993LV35100016

    View details for PubMedID 8405200

  • CHARACTERISTICS RELATING TO OVARIAN-CANCER RISK - COLLABORATIVE ANALYSIS OF 12 UNITED-STATES CASE-CONTROL STUDIES .6. NONEPITHELIAL CANCERS AMONG ADULTS EPIDEMIOLOGY HORNROSS, P. L., Whittemore, A. S., Harris, R., ITNYRE, J. 1992; 3 (6): 490-495

    Abstract

    Nonepithelial ovarian cancers are rare, and little is known about their etiology. Of particular interest are the effects of oral contraceptive use and pregnancy, both of which are associated with large decreases in risk for epithelial ovarian cancer. We examined the risk factors for nonepithelial ovarian tumors by combining data from four case-control studies conducted in the United States. We compared personal characteristics of 38 germ cell cases and 45 stromal cases, respectively, with 1,142 and 2,617 general population controls. All subjects were over age 18 years. For germ cell tumors, there was a weak negative association with parity but no consistent pattern of decreasing risk with increasing parity. In contrast, relative to nulligravid women, gravid nulliparous women were at increased risk of developing a germ cell cancer [odds ratio (OR) = 4.8, 95% confidence interval (CI) = 1.2-18.6]. The use of oral contraceptives was also associated with elevated risk (OR = 2.0, 95% CI = 0.77-5.1); however, no clear trends in risk were observed. For stromal tumors, oral contraceptive use was associated with decreased risk (OR = 0.37, 95% CI = 0.16-0.83), whereas pregnancy was associated with a small elevation in risk. A trend of increasing risk with increasing age at first term pregnancy was observed, with an odds ratio of 3.6 (95% CI = 1.0-12.5) for a first birth after age 29 years. Risk factors for nonepithelial ovarian cancers do not appear to parallel each other or those for epithelial ovarian cancer.

    View details for Web of Science ID A1992JY33700005

    View details for PubMedID 1329996

  • RECENT TRENDS IN THE INCIDENCE OF SALIVARY-GLAND CANCER INTERNATIONAL JOURNAL OF EPIDEMIOLOGY HORNROSS, P. L., West, D. W., Brown, S. R. 1991; 20 (3): 628-633

    Abstract

    Beginning in 1985, a sudden and sustained doubling of salivary gland cancer incidence, among men only, is observed in the San Francisco-Oakland Metropolitan Statistical Area. Registry data are examined to determine the nature of this increase and its possible association with the AIDS epidemic. Changes in patient characteristics are assessed by comparing their distribution among recently diagnosed cases (1985-1988) to an expectation based on population growth and the age-specific incidence among patients diagnosed earlier (1973-1984). Based on the observed patterns, it is unlikely that the temporal increase in these tumours is a direct result of the AIDS epidemic or solely the result of a shift in the prevalence of established risk factors. The increase is predominantly seen in men over the age of 75 at diagnosis (O/E = 2.3, p = 0.02) and is observed among both those with and without a prior cancer (O/E = 2.7, p = 0.02 and O/E = 1.5, p = 0.06, respectively). Radiation for the prior cancer was not associated with increased occurrence. Military exposure is crudely approximated by examining birth cohorts. However, the cohort data do not support a hypothesis of military exposure.

    View details for Web of Science ID A1991GJ74000007

    View details for PubMedID 1955246

  • TEMPORAL TRENDS IN THE INCIDENCE OF CUTANEOUS MALIGNANT-MELANOMA AMONG CAUCASIANS IN THE SAN-FRANCISCO-OAKLAND MSA CANCER CAUSES & CONTROL HORNROSS, P. L., Holly, E. A., Brown, S. R., Aston, D. A. 1991; 2 (5): 299-305

    Abstract

    Temporal changes in the incidence of cutaneous malignant melanoma (CMM) were examined in the San Francisco-Oakland (California, United States) Metropolitan Statistical Area (MSA) between 1976 and 1987, using data from the population-based cancer registry. This analysis was conducted after the completion of a project designed to eliminate bias in the reporting of CMM due to changes in medical practice. The incidence of CMM is higher in the San Francisco-Oakland MSA than nationally. From 1976 through 1987, the incidence of invasive CMM increased from 9.8 +/- 0.9 to 16.5 +/- 1.1 per 100,000 (P = 0.0001) among men and from 9.3 +/- 0.8 to 12.7 +/- 0.9 per 100,000 (P = 0.001) among women. Age-specific, histologic-specific, and anatomic site-specific trends were also evaluated. The temporal patterns of CMM suggest that the recent increases are not accounted for solely by ascertainment bias due to reporting practices. The observed trends are consistent with early detection efforts and with changes in the prevalence of risk factors.

    View details for Web of Science ID A1991GF18300003

    View details for PubMedID 1932542

  • TEMPORAL TRENDS IN THE INCIDENCE OF NON-HODGKINS LYMPHOMA AND SELECTED MALIGNANCIES IN A POPULATION WITH A HIGH-INCIDENCE OF ACQUIRED IMMUNODEFICIENCY SYNDROME (AIDS) AMERICAN JOURNAL OF EPIDEMIOLOGY Horn, P. L., DeLorenze, G. N., Brown, S. R., Holly, E. A., West, D. W. 1989; 130 (5): 1069-1070

    View details for Web of Science ID A1989AY60100027

    View details for PubMedID 2816897

  • RISK OF CONTRALATERAL BREAST-CANCER - ASSOCIATIONS WITH FACTORS RELATED TO INITIAL BREAST-CANCER AMERICAN JOURNAL OF EPIDEMIOLOGY Horn, P. L., Thompson, W. D. 1988; 128 (2): 309-323

    Abstract

    A case-control study was conducted to assess the risk factors associated with the development of a contralateral primary breast cancer among women who had had a first primary breast cancer. Hospital records were reviewed for 292 women who had an incident contralateral breast cancer, diagnosed in one of eight Connecticut hospitals between July 1, 1975 and December 31, 1983, and for a comparison group of 264 surviving unilateral breast cancer patients previously diagnosed in the same hospitals. All subjects were identified through the records of the Connecticut Tumor Registry. A family history of breast cancer in any first- or second-degree relative was associated with an almost threefold increased risk of developing a contralateral cancer (adjusted odds ratio (OR) = 2.8, 95% confidence interval (CI) = 1.6-4.9). Further, this relation was modified by the time elapsed since the initial cancer diagnosis (ratio of OR = 1.9, 95% CI = 1.2-3.0 for a five-year differential in time since initial diagnosis). A delay of 10 years in first full-term pregnancy was associated with a 36% decrease in risk (adjusted OR = 0.6, 95% CI = 0.3-1.2); this estimate excluded the magnitude of increased risk usually observed in studies of initial breast cancer. A conceptual framework is presented for assessing the study findings in the context of previous studies that have examined the corresponding associations for initial primary breast cancers.

    View details for Web of Science ID A1988P404600008

    View details for PubMedID 3394698

  • RISK OF CONTRALATERAL BREAST-CANCER - ASSOCIATIONS WITH HISTOLOGIC, CLINICAL, AND THERAPEUTIC FACTORS CANCER Horn, P. L., Thompson, W. D. 1988; 62 (2): 412-424

    Abstract

    A case-control study was conducted to assess the risk factors associated with the development of a contralateral primary breast cancer among women who had had a first primary breast cancer. Hospital records were reviewed for 292 women with an incident contralateral breast cancer, diagnosed in one of eight hospitals between July 1, 1975 and December 31, 1983, and for a comparison group of 264 surviving unilateral breast cancer patients, previously diagnosed in the same hospitals. All subjects were identified through the records of the Connecticut Tumor Registry. Having an initial tumor containing lobular carcinoma was associated with an almost twofold increased risk of developing a contralateral cancer (aOR = 1.8; 95% CI: 1.0-3.5). Among those for whom a progesterone receptor assay was available, a positive assay was associated with an increased risk of a contralateral primary (aOR = 3.2; 95% CI: 1.0-9.5). AB blood type was also associated with an elevated risk, but this elevation was not statistically significant (aOR = 2.3; 95% CI: 0.7-7.7). Having received radiation treatment was not significantly associated with the risk of a contralateral primary (aOR = 0.9; 95% CI: 0.6-1.4), whereas chemotherapy treatment was associated with a significantly lowered risk (aOR = 0.3; 95% CI: 0.1-0.7). The association with chemotherapy appeared to be modified by body build (ROR = 1.5; 95% CI: 1.0-2.3 for a 2.5-unit differential in Quetelet's index).

    View details for Web of Science ID A1988P057000027

    View details for PubMedID 3383140

  • EXPOSURE TO CHEMOTHERAPEUTIC-AGENTS AND THE RISK OF A 2ND BREAST-CANCER - PRELIMINARY FINDINGS YALE JOURNAL OF BIOLOGY AND MEDICINE Horn, P. L., Thompson, W. D. 1988; 61 (3): 223-231

    Abstract

    Chemotherapeutic treatment for cancer has been successful in prolonging survival but may also lead to the development of second cancers. Two case-control studies presented here suggest, however, that breast cancer patients who receive chemotherapy are at significantly lower risk of a contralateral breast cancer than those who do not. Approximately 300 incident cases of contralateral breast cancer and 300 randomly chosen surviving controls with unilateral breast cancer were identified through the Connecticut Tumor Registry for inclusion in each study. The initial study was based on review of medical records at eight hospitals and indicated that the overall association with chemotherapy was modified by body build. The second study obtained information from in-person interviews, hospital records, and outpatient chemotherapy records from across the state. The preliminary results of this second study confirm the previous findings. Both cytotoxic and hormonal drugs were associated with a reduction in the risk of second breast cancers (OR = 0.5, 95 percent CI: 0.3-1.0; OR = 0.5, 95 percent CI: 0.2-1.2, respectively). Significant interaction with body build was observed for hormonal treatment (ratio of ORs = 5.8, 95 percent CI: 1.0-34.3 for a five-unit change in Quetelet's index), with a nonsignificant but detrimental effect suggested for overweight women (OR = 2.3, 95 percent CI: 0.4-13.9 for a Quetelet's score of 35).

    View details for Web of Science ID A1988P938900005

    View details for PubMedID 3176526

  • DYSPLASTIC NEVI IN ASSOCIATION WITH MULTIPLE PRIMARY MELANOMA CANCER RESEARCH TITUSERNSTOFF, L., Duray, P. H., Ernstoff, M. S., Barnhill, R. L., Horn, P. L., Kirkwood, J. M. 1988; 48 (4): 1016-1018

    Abstract

    Risk factors for multiple primary cutaneous melanoma were evaluated in a case-control study. Eight cases of multiple primary melanoma were matched on sex, age, and education to 24 first primary melanoma controls. Risk factors examined in the analysis included pigmentary characteristics, history of sun exposure, and nevi. The importance of histologically dysplastic nevi (DN) and clinically atypical nevi was of particular interest. Single-factor conditional logistic regression analysis showed that first primary melanoma patients with histological DN are at increased risk for a second primary (odds ratio, 6.2; 95% confidence interval, 1.2-33.4). Patients with two or more clinically atypical nevi also have elevated risk for a second primary (odds ratio, 8.8; 95% confidence interval, 1.0-80.7). Two-factor logistic models were used to evaluate the effect of histological DN while controlling singly for all other variables as potential confounders. Odds ratios for the association of histological DN varied from 6.1 to 10.4 when adjusting singly for pigmentary and sun exposure variables. In the two-factor model that included histological and clinical DN, both variables retained marginally significant statistical association with multiple primary melanoma. These results suggest that DN is a marker of increased risk for multiple primary melanoma and suggest that melanoma patients with evidence of DN should be followed closely for the development of additional primaries.

    View details for Web of Science ID A1988M081500045

    View details for PubMedID 3338073

  • FACTORS ASSOCIATED WITH THE RISK OF 2ND PRIMARY BREAST-CANCER - AN ANALYSIS OF DATA FROM THE CONNECTICUT TUMOR REGISTRY JOURNAL OF CHRONIC DISEASES Horn, P. L., Thompson, W. D., Schwartz, S. M. 1987; 40 (11): 1003-1011

    Abstract

    To examine further the epidemiology of contralateral primary breast cancer, a case-control analysis, utilizing information available from the Connecticut Tumor Registry, was conducted. Recent cases of second primary breast cancer were compared to control women who had survived a first breast cancer but had not developed a second. Three hundred and thirty eight incident cases of contralateral breast cancer diagnosed between 1979 and 1982 were identified and compared with an equal number of randomly selected controls and 336 controls frequency matched to the cases on the basis of age at initial cancer diagnosis and the calendar time elapsing since that diagnosis. Risk of second primary breast cancer was found to be significantly elevated among women whose initial cancer was lobular carcinoma and during the first year following diagnosis of the initial primary. Additionally, for women initially treated with radiotherapy, risk of a contralateral primary increased for 10-14 years following treatment, after which it declined. Among young women, having never married was protective whereas the opposite was found among older women. These findings and the methods used are discussed in the context of the epidemiology of both contralateral and initial breast primaries.

    View details for Web of Science ID A1987K213900002

    View details for PubMedID 3654901

  • REPRODUCIBILITY OF THE CYTOLOGIC DIAGNOSIS OF HUMAN PAPILLOMAVIRUS INFECTION ACTA CYTOLOGICA Horn, P. L., Lowell, D. M., LiVolsi, V. A., Boyle, C. A. 1985; 29 (5): 692-694

    Abstract

    As part of a larger epidemiologic investigation of the association between human papillomavirus (HPV) infection and cervical intraepithelial neoplasia, the reliability of the cytologic diagnosis of HPV infection was examined. A random sample of cervicovaginal specimens with cytologic changes characteristic of HPV infection were matched with a second set of slides, with regard to the date and severity of the smear and the age of the woman from whom the smear was obtained. The kappa statistic for interobserver agreement was 0.38 (p less than 0.0005), increasing to 0.68 (p less than 0.0005) when uncertain diagnoses were excluded. Intraobserver agreement ranged from kappa = 0.40 to 1.00. Although this agreement is within the range of reliability found for the diagnosis of other atypical cytologic changes, considerable variation is present. The effect of this variability on the validity of estimating the risk of cervical cancer associated with HPV infection may be considerable.

    View details for Web of Science ID A1985ASA8300007

    View details for PubMedID 2996269

  • INTELLIGENCE AND ACHIEVEMENT OF ADULT ILLITERATES IN A TUTORIAL PROJECT - A PRELIMINARY-ANALYSIS JOURNAL OF CLINICAL PSYCHOLOGY GOLD, P. C., Horn, P. L. 1983; 39 (1): 107-113

    Abstract

    Reports the results of preliminary analyses of intelligence and achievement in an adult tutorial project. Incarcerated adult illiterates volunteered to participate in a peer tutoring program wherein they received 27 hours of structured tutoring. Significant achievement was demonstrated in all areas. Achievement and gains in achievement were analyzed in relation to Verbal, Performance, and Full Scale IQ scores using four sets of analyses. Significant correlations were noted between IQ scores and achievement, but not gains in achievement. Gains in achievement were not significantly different among Ss at different Verbal, Performance and Full Scale IQ levels, nor were gains in achievement different between Ss who had a significant Verbal-Performance discrepancy and those who did not. Gains in achievement were not significantly different across subgroups categorized according to both IQ level and Verbal-Performance discrepancy.

    View details for Web of Science ID A1983QA21100020

    View details for PubMedID 6826738

  • ACHIEVEMENT IN READING, VERBAL LANGUAGE, LISTENING COMPREHENSION AND LOCUS OF CONTROL OF ADULT ILLITERATES IN A VOLUNTEER TUTORIAL PROJECT PERCEPTUAL AND MOTOR SKILLS GOLD, P. C., Horn, P. L. 1982; 54 (3): 1243-1250

    Abstract

    This study examined the effectiveness of specific psychoeducational tutoring methods on achievement in reading, verbal language, listening comprehension, and locus of control. Subjects were 76 youths and adults reading below fifth grade who volunteered to participate in an adult tutorial project. After the assessment of entry level achievement, subjects were tutored for 34 hr. by trained volunteers. Comparison of pretest and posttest scores with a control group that received no tutoring indicated that subjects made significant improvement in both general reading and discrete reading subskills. As gains in verbal language, listening comprehension, and locus of control were nonsignificant, further research is needed over a longer period of time or employing other standardized measures. Results support the use of well-trained volunteers in ameliorating problems of adult illiteracy.

    View details for Web of Science ID A1982NV51900045

    View details for PubMedID 7110868

Conference Proceedings


  • Predictors of misclassification of Hispanic ethnicity in a population-based cancer registry Swallen, K. C., West, D. W., Stewart, S. L., Glaser, S. L., HORNROSS, P. L. ELSEVIER SCIENCE INC. 1997: 200-206

    Abstract

    Hispanic ethnicity is often used as a category for calculating population-based rates or assessing risk of epidemiologic studies. However, ethnic misclassification can lead to false conclusions unless the extent of misclassification and the characteristics of those misclassified are understood.This study explored determinants of ethnic misclassification in a sample of 1154 cancer cases in the San Francisco-Oakland cancer registry, where ethnic classification is based on surname or medical record report. We compared the following: correctly classified Hispanics, persons classified as Hispanic who self-identified as non-Hispanic, and persons classified as non-Hispanic who self-identified as Hispanic.Among men classified as Hispanic, those most likely to self-identify as non-Hispanic did not speak Spanish, had non-Spanish surnames, and were recent immigrants. Women misclassified as Hispanic did not speak Spanish or have Spanish maiden names, nor did they have mothers with Spanish maiden names. Persons who called themselves Hispanic, but were misclassified by the registry, were likely to be non-Spanish speaking college-education males.Researchers using ethnicity should be aware of how ethnicity was determined and how this classification may bias or confound their results.

    View details for Web of Science ID A1997WX57800007

    View details for PubMedID 9141643

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