Association of socioeconomic and clinical factors with overall survival in immunotherapy-eligible stage III non-small cell lung cancer following definitive chemoradiation.

Abstract

1522 Background: Use of consolidative immunotherapy (IO) for stage III non-small cell lung cancer (NSCLC) has increased since FDA approval in 2018, yet disparities in access persist. Few studies have examined survival in the IO era accounting for both socioeconomic and clinical factors. We evaluated determinants of overall survival (OS) in IO-eligible patients (pts) after definitive chemoradiation (CRT). Methods: Retrospective National Cancer Database analysis was performed, of adults ≥18 years with stage III NSCLC (2018-2020) receiving ≥60 Gray in ≥30 fractions of RT with known IO status, defined as receipt 50-150 days from CRT start. Surgical cases were excluded. Variables included race/ethnicity (R/E), insurance, facility type, Charlson-Deyo comorbidity index (CCI), high school graduation rate (HSGR), household income, sex, age, NSCLC primary site, and histology. OS was assessed using the Kaplan-Meier method, followed by multivariable Cox regression models adjusting for aforementioned variables, including IO receipt. Results: Among 19,418 pts, 54.4% received IO. Median age was 68 years; 44% were female; 85% White, 12.5% Black, 2% Asian, and 2% Hispanic. Median OS was higher with IO (42.1 vs 22.3 months [mo], P <.001) and in females (38.8 vs 28.1 mo, P <.001). OS differed by R/E: Asian (52 mo), Black (40.3 mo), Hispanic (37.2 mo), American Indian/Alaska Native (24 mo) vs White pts (31.1 mo), P <.001. Privately insured pts (41.7 mo) and those treated at academic/research (A/R) centers (36.5 mo) had higher OS ( P <.001). On multivariable analysis, IO receipt was associated with lower all-cause mortality (HR 0.53; 95% CI, 0.51-0.56). Reduced mortality was seen in Asian (HR 0.82; 95% CI, 0.68-0.99) and Black pts (HR 0.83; 95% CI, 0.77-0.89) vs White pts. Higher mortality was associated with male sex (HR 1.28; 95% CI, 1.22-1.34), urban (non-metropolitan) vs metropolitan residence (HR 1.14; 95% CI, 1.07-1.22), Medicare (HR 1.10; 95% CI, 1.03-1.18) or no insurance (HR 1.36; 95% CI, 1.14-1.63) vs private insurance, nonacademic facilities (comprehensive: HR 1.09; 95% CI, 1.03-1.16; integrated network: HR 1.15; 95% CI, 1.07-1.23), and CCI of 2 (HR 1.13; 95% CI, 1.04-1.21) or ≥3 (HR 1.29; 95% CI, 1.19-1.40). Income and HSGR showed marginal association with OS. Upper-lobe vs main bronchus sites were associated with better OS ( P <.02), while squamous histology was associated with worse OS ( P <.001). Conclusions: Approximately half of IO-eligible stage III NSCLC pts received IO, which was independently associated with improved OS, adjusting for socioeconomic and clinical factors. Asian and Black race, and treatment at A/R centers, were associated with lower mortality. Insurance and facility type significantly influenced OS, highlighting persistent access-related disparities and the need for targeted interventions to promote equitable care.