When it comes to cancer prevention, certain body parts get more due diligence than others.
Lung cancer is the leading cancer killer of both men and women in the U.S., but you wouldn’t know it by the attention it receives. Only 5% of those eligible for lung cancer screening receive the recommended imaging. In contrast, 72% of women eligible for breast cancer screening undergo regular mammograms, and a similar percentage of eligible men and women are screened for colon cancer. That’s despite the fact that lung cancer kills around 50% more women than breast cancer every year in the U.S.
As in other kinds of cancer, screening can make a big difference for lung cancer. It’s the deadliest cancer in large part because it’s usually detected at late stages, when prognoses are poor. If it’s caught early, survival rates are much better — five-year survival for early-stage lung cancer is more than seven times as high as that for lung cancer that has metastasized. But early-stage lung cancer usually doesn’t cause any symptoms, so screening is key to catching it.
The U.S. Preventive Services Task Force recommends that people aged 50-80 years who smoke or recently smoked an average of a pack a day of cigarettes for 20 or more years undergo a yearly CT scan of the lungs. Nearly 14 million Americans are estimated to be eligible for screening under these guidelines, but uptake of the screening is low. Lung cancer can also occur in those who don’t smoke, and it’s on the rise in never-smokers, but screening is only recommended for current smokers or those who quit in the last 15 years.
Five-year survival for early-stage lung cancer is more than seven times as high as that for lung cancer that has metastasized. But early-stage lung cancer usually doesn’t cause any symptoms, so screening is key to catching it.
Stanford Medicine’s Leah Backhus, MD, the Thelma and Henry Doelger Professor in Cardiovascular Surgery II, and her colleagues came up with a creative approach to boost lung cancer screening: Combine it with a mammogram.
Backhus and her colleagues recently led a study testing this idea in 54 women eligible for dual screening who agreed at their mammogram appointments to also receive CT scans to check for lung cancer. The researchers published an article describing their results in the Journal of Surgical Research in March.
We spoke with Backhus to learn more about the study and how she hopes this approach could lead to better uptake. This interview has been edited for length and clarity.
Why do so few eligible people get screened for lung cancer?
Every time I speak publicly, I’ll ask for a show of hands: Who’s heard of mammography for breast cancer? Who’s heard of pap smears? And who’s heard of lung cancer screening? It’s always a major difference; people don’t know about lung cancer screening.
There are a lot of reasons for that. One is that it’s newer — the U.S. Preventative Services Task Force recommended lung cancer screening in 2013 and updated its guidelines in 2021 — and has had less time to mature as a guideline. And there’s a lack of awareness among primary care providers, who are the main portal of entry for most screening interventions.
How did your study come about?
The idea came about from a task group focused on lung cancer in women as part of the National Lung Cancer Roundtable. One of the ideas was to combine lung cancer screening with mammograms. Two of the members of the task group, Kim Sandler, MD, a radiologist at Vanderbilt University, and Carey Thomson, MD, a pulmonologist at Mount Auburn Hospital, had already been collaborating on this idea, then Stanford came on as a third site with some funding through the Stanford Cancer Center.
What did you find?
We’ve published a few papers on dual screening now. The first was to show that there’s a reasonable amount of overlap between women who are eligible for breast cancer screening and lung cancer screening. The next study looked at rates of screening: When we reached out to people who were eligible, how many were receptive? We found that a little more than half of the eligible women were willing to undergo lung cancer screening together with their mammograms. In our most recent study, we surveyed the patients who underwent dual screening to find out more about their awareness of and attitudes toward lung cancer screening. Their attitudes were overwhelmingly positive.
The rest of the survey results cemented what we already knew to be true, which is that most people are not aware of lung cancer screening. Since they are smokers or former smokers, most of the women in the study thought they had a high risk of lung cancer and were concerned about it. Many of them were concerned about cost, even though it is considered part of routine health screening so insurance will fully cover it. So, it goes to show there’s a lack of awareness regarding the finances.
Most of the women in the study thought they had a high risk of lung cancer and were concerned about it.
Do you envision this kind of dual screening could be implemented more broadly?
Yes, and we’re starting to hardwire it into clinics at Stanford Medicine. One barrier is that it’s difficult to automatically identify eligible patients from their electronic health records, largely because smoking history is not documented consistently. Our colleagues at Vanderbilt are working on an automation method, but for our studies we had two industrious medical students and a resident who went through medical records manually to find women who were eligible for both kinds of screening. We’re still trying to figure out how we can scale this up at Stanford Medicine.
Are you looking into any other kinds of dual screening?
It’s funny you should ask, because right now I’m exploring whether we can combine lung cancer screening with men and women who are coming in for cardiac coronary angiograms. This would be really convenient for patients because those angiograms are also a CT scan, so it would just be a matter of expanding the scan, with the patient’s consent, and getting a look at their lungs as well as their heart. With the mammogram and lung cancer screening, it’s two separate kinds of imaging. My hypothesis is that a lot of the patients coming in for angiograms will also be eligible for lung cancer screening, because there’s an overlap with smoking and cardiovascular disease risk.
