Exploring social determinants of health and immunotherapy utilization in patients with stage III non-small-cell lung cancer after definitive chemoradiation

Background Since the 2018 Food and Drug Administration approval of immunotherapy (IO) for consolidative therapy in stage III non-small-cell lung cancer (NSCLC), real-world uptake across racial and socioeconomic groups remains poorly characterized. This study evaluated IO utilization patterns after definitive chemoradiation (CRT) in a diverse national cohort. Materials and methods A retrospective analysis was carried out using the National Cancer Database for patients aged ≥18 years diagnosed with stage III NSCLC from 2018 to 2021. Inclusion criteria included receipt of ≥60 Gy of radiation in ≥30 fractions, and IO administered 50-150 days from CRT initiation. Surgical cases were excluded. Social determinants of health included race, ethnicity, insurance type, treatment facility, Charlson-Deyo comorbidity index, high school graduation rate (HSGR), income, sex, and age. Odds ratios (ORs) were calculated using univariable and multivariable logistic regression, and multicollinearity was tested via Cramér V. Results Among 25 746 patients, 21 848 were white, 3236 black, 558 Asian, 104 American Indian or Alaska Native, and 620 Hispanic. Univariable analysis showed lower IO use among black (OR 0.86), Hispanic (OR 0.72), Mexican (OR 0.45), and South Asian (OR 0.48) patients, those with Medicare (OR 0.94), treated at community sites (OR 0.88), and from lower HSGR and income areas (ORs ≤ 0.90), all P < 0.05. Multivariable analysis confirmed reduced IO use in these groups, except for income. Income lost its independent significance in multivariable analysis, likely reflecting its collinearity with HSGR (Cramér V=0.37). Conclusion Disparities in IO receipt persist after CRT for stage III NSCLC in the post-IO era, highlighting the need to address systemic barriers to equitable cancer care.