Brief Report on Sociodemographic Patterns of Lung Cancer in Individuals Who Never Smoked.

INTRODUCTION: Lung cancer in individuals who never smoked (LCINS) is a distinct disease, not captured by existing smoking-based screening guidelines. As smoking rates decline, people who have never smoked represent a growing share of the lung cancer burden. It remains unknown whether this burden falls disproportionately across distinct demographic subgroups. Understanding these trends is critical for informing screening policy and reducing disparities. We sought to evaluate the proportion of LCINS over time and characterize variation across key demographic subgroups in a large, diverse cohort. METHODS: We performed a retrospective chart review of 5,131 non-small cell lung cancer (NSCLC) patients treated at a single urban academic institution (2005-2024). Joinpoint regression analysis evaluated temporal trends in the proportion of new LCINS diagnoses and multivariable logistic regression assessed associations with never-smoking status and key factors, including sex, age and race/ethnicity. RESULTS: LCINS comprised 13.9% (n=715) of cases overall and increased from 12.3% in 2005 to 18.0% in 2024 (annual percent change [APC] 1.53%, p=0.021). Female sex (aOR 2.48, p<0.001), age<50 (aOR 2.41, p<0.001) and >80 (aOR 2.12, p<0.001), Black race (aOR 1.24, p=0.040), and Hispanic ethnicity (aOR 1.69, p<0.001) were independently associated with LCINS. Stratified analyses demonstrated increasing LCINS proportions among females (1.40%, p=0.040), specifically Hispanic women (APC 2.36%, p=0.019). CONCLUSION: LCINS proportions are increasing over time and demonstrated marked sex- and race/ethnicity-based trends. Hispanic women appear to represent a particularly high-risk subgroup. These findings highlight the need for continued investigation into risk-adapted strategies that incorporate factors beyond smoking into screening.