Stanford Cancer Institute

​​A study led by SCI members Summer Han, PhD, and Eunji Choi, PhD, and graduate student Chloe Su found that lung cancer survivors who have never smoked have the same risk as survivors who have smoked of developing secondary primary lung cancer (SPLC), which is cancer that spreads to the lungs from somewhere else in the body.

Previous research shows that individuals diagnosed with initial primary lung cancer (IPLC), lung cancer that originates in the lungs, have a four- to six-fold increased risk of developing SPLC. Prior studies have identified tobacco smoking as a risk factor for SPLC, and many studies have investigated the SPLC risk among lung cancer survivors who have smoked, but little research has been conducted on SPLC incidence among survivors who have never smoked. 

This study looked at large, diverse, population-level data with long-term follow-up to determine the incidence of SPLC in different groups. While the incidence of IPLC in the general population was seven times higher for current and former smokers compared to non-smokers, the incidence of SPLC following an IPLC diagnosis was as high among those who ever smoked (2.84%) as those who never smoked (2.72%). This observation was consistently observed by sex subgroups, as well as among key subgroups of those with early-stage initial disease and those with adenocarcinoma histology in initial disease.

Han, the study’s principal investigator, said, “The reasons behind the elevated risk of SPLC among never-smoking lung cancer survivors are still poorly understood. A targeted and tailored surveillance strategy is needed for this population of patients given their differential survival profile and potentially distinct risk factors for SPLC.”

This study was supported by grants 4R37CA226081 and 1RO1CA282793 from the NIH and the Stanford Cancer Institute. A full list of collaborating authors and their disclosures can be found in the full paper. The study was published in JAMA Network Open and is available at this link.

December 2023 by Katie Shumake