ScholarWorks@성균관대학교

초록

Background: Although lung cancer screening programs aimed at high-risk adults who smoke have effectively reduced mortality rates, the risk factors for lung cancer in people who have never smoked (LCINS) remain poorly understood. Research Question: What are the risk factors of LCINS? Study Design and Methods: This multicenter, retrospective, age- and sex-matched case-control study included only people who have never smoked. Case patients were diagnosed with non-small cell lung cancer at tertiary centers in the South Korea between 2016 and 2020. Control patients were individuals who underwent opportunistic chest CT scans with negative findings at the same centers during the same period. Results: A total of 3,000 case patients and 3,000 matched control patients were analyzed. The median age was 60 years, and 81.1% were female. Among case patients, stage I disease was most common (66.7%). There was no statistically significant association between a first-degree family history of lung cancer and driver mutations. Adjusted multivariable conditional logistic regression identified chronic lung disease (adjusted OR [aOR], 2.91; 95% CI, 2.35-3.59; P < .001), noncapital region residence (aOR, 2.81; 95% CI, 2.49-3.17; P < .001), unemployment (aOR, 1.32; 95% CI, 1.14-1.53; P < .001), and first-degree family history of lung cancer (aOR, 1.23; 95% CI, 1.02-1.49; P = .028) as independent risk factors for non-small cell lung cancer. In contrast, undergraduate-level or higher education (aOR, 0.53; 95% CI, 0.44-0.63; P < .001) was associated with a lower risk of LCINS. These associations showed consistent directional trends across age- and sex-stratified subgroups; however, some estimates did not reach statistical significance. Interpretation: Our results indicate that both environmental and host factors contribute to LCINS. A multifactorial risk assessment approach is warranted to better identify high-risk populations among people who have never smoked.

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