Clinical characteristics and risk factors of individuals ineligible for lung cancer screening at a tertiary care center.

10529 Background: Lung cancer screening (LCS) reduces mortality, yet many individuals with lung cancer do not meet the 2021 USPSTF eligibility criteria. We compared clinical characteristics and risk factors in individuals with lung cancer who were ineligible and eligible for LCS. Methods: We conducted a retrospective study of individuals with a new or prior diagnosis of lung cancer at Indiana University Health from April 1, 2025 - December 4, 2025. We recruited individuals during their clinic visits and used electronic medical records and a patient-completed survey to obtain demographic information, smoking history, and lung cancer risk factors at diagnosis (high-risk lung disease/occupation, first-degree family history of lung cancer, autoimmune disease, prior chest-wall radiation). Individuals were stratified using the 2021USPSTF criteria. Continuous and categorical variables were compared with T-tests and χ²/Fisher’s exact tests. Logistic regression models were used for multivariate analysis. Results: 242 individuals were evaluated and 128 (53%) were ineligible for LCS. The median age was 63 among ineligible individuals, 56% were female, 70% were white, and 25% were black (64, 55%, 80%, and 17% respectively among LCS eligible). These individuals were more likely to have adenocarcinoma (80% vs. 56%, p <0.001) and present with stage IV disease compared to those eligible for LCS [51% vs. 26%, adjusted OR 2.13 (95% CI, 1.01 – 4.57), p =0.048]. Of note, 24 individuals (19%) were <50 or >80 years old and 46 (36%) were never-smokers; however, tobacco exposure was common (64% ever-smokers, 21% used other tobacco products, 56% secondhand exposure). Most of these individuals had high-risk lung disease (61%), Table. Multivariate analysis adjusting for smoking revealed no association between LCS eligibility and secondhand exposure or high-risk occupation, p =0.340 and 0.275. Interestingly, 1/3 of individuals in both cohorts had a first-degree relative with lung cancer. Conclusions: Most individuals with lung cancer in our cohort were ineligible for LCS using the 2021 USPSTF criteria and were more likely to present with metastatic disease. Many had significant tobacco exposure and other risk factors similar to those eligible for LCS. Our findings suggest the current LCS criteria exclude a large at-risk population and should be re-evaluated to account for risk factors beyond age and pack-years. Risk Factor Ineligiblen=128 (%) Eligiblen=114 (%) p Ever-smokers (≥ 100 cigarettes) 82 (64.1) 114 (100) <0.001 Use of Other Tobacco Product 27 (21.1) 47 (41.2) <0.001 High-Risk Lung Disease (e.g., COPD) 78 (60.9) 95 (83.3) <0.001 Secondhand Smoking 71 (55.5) 79 (69.3) 0.340* High-Risk Occupation (e.g., firefighting) 47 (36.7) 58 (50.9) 0.275* 1 st Degree Family History 42 (32.8) 40 (35.1) 0.343 Autoimmune Disease 12 (9.4) 10 (8.8) 1.000 Chest Wall Radiation 11 (8.6) 11 (9.6) 0.951 *Adjusted for smoking.