Lung cancer risk in persons enrolled in low-dose CT screening (LDCT) versus incidental lung nodule programs (ILNP).

Abstract

8553 Background: LDCT screening saves lives, but <10% of eligible persons participate; eligibility criteria are imperfect; geographic, racial and socio-economic disparities have emerged. ILNP may expand access to early detection. We compared rates of lung cancer diagnosis in LDCT and ILNP population subsets. Methods: Prospective observational cohort study of enrollees in LDCT and ILNP in a community healthcare system in AR, MS and TN. We compared LDCT vs 4 ILNP cohorts (C) based on USPSTF 2021 LDCT eligibility criteria: <50 years (C1, too young); >80 years (C2, too old); 50 – 80 years (C3, ineligible smoking history); 50 – 80 years (C4, eligible). For certain analyses, we stratified the LDCT cohort by baseline (T0) Lung-RADS score (0-2 v 3-4). We used a Cox model to calculate crude and adjusted hazard ratios (aHR) for lung cancer diagnosis within 24 months of enrollment. Results: From 2015-2021, 7050 persons were in LDCT- 6073 (86%) Lung-RADS 0-2 (no/benign lesions), 977 (14%) Lung-RADS 3 or 4 (possibly malignant lesion) on T0 scan; 17,579 were in ILNP, 16%, 10%, 57% and 16% respectively in C1-4. Demographics and tobacco use history of the ILNP cohorts differed strikingly; C4 was very similar to LDCT (Table). Black persons were significantly more in C1 (too young) and C3 (insufficient tobacco use). Diagnosis of lung cancer at 36 months ranged from 1% in C1 to 15% in C4, compared to 3% in LDCT; aHR for lung cancer diagnosis within 2 years ranged from 0.23 to 5.12 (all LDCT ref), but ranged from 0.04 to 1.02 with reference to LDCT Lung-RADS 3-4. Most patients in LDCT and ILNP C2-4 had early stage. There were proportionately more Black lung cancer patients in C1-4, and 3 times more Black patients in C3 and 4 than in LDCT. Conclusions: ILNP provides early-detection access to a larger, more diverse population than LDCT, potentially alleviating race and socio-economics-based outcomes disparities. [Table: see text]