Abstract B161: Urban-rural and racial disparities in the uptake of Immune Checkpoint Inhibitor (ICI) treatments for non-small cell lung cancer (NSCLC) – A population-based study

Abstract Background While ICIs have revolutionized NSCLC management, studies on real-world ICI uptake are limited. Before ICIs became the standard of care, NSCLC research uncovered inequities in treatment outcomes by race and other social determinants, like rurality. It is unclear if similar disparities exist for ICI treatment. To understand these disparities, this population-based study aims to investigate differences in ICI treatment uptake by race and rurality among late-stage NSCLC patients. Methods The SEER-Medicare database was used to identify patients 3 66 years diagnosed with stage III or IV NSCLC, with continuous Medicare coverage beginning ≥ 12 months prior to diagnosis, and a self-reported race of Black or White. ICI treatment uptake was analyzed between January 1, 2014, and December 31, 2019. ICI uptake was defined as the use of an ICI at any point after NSCLC diagnosis. Rurality was identified using SEER’s Rural-Urban Continuum Codes 04-09. A multivariable logistic regression model was used to assess the likelihood of receiving ICI treatment, adjusting for age, year of diagnosis, sex, race, rurality, Charlson comorbidity index, cancer histology, dual eligibility for Medicaid, and state Medicaid buy-in. A Fine-Gray hazards model with mortality as a competing risk was used to estimate time to ICI treatment, adjusting for the same variables as the logistic regression. Results Of the 17,288 patients identified with NSCLC, 3,168 (18.3%) lived in rural areas and 14,120 (81.7%) in urban areas; 1,316 (7.6%) were Black and 15,972 (92.4%) were White. ICI treatment uptake increased from 8.5% of patients diagnosed in 2014 to 31.3% in 2017. The odds of ICI uptake were 26% lower in rural patients compared to urban patients (aOR=0.74; 95% CI, 0.67-0.82), and 15% lower in Black patients compared to White patients (aOR=0.85; 95% CI, 0.725-0.984). Among rural patients with NSCLC, 15.1% had used ICIs within 2 years of diagnosis, compared to 18.5% of urban counterparts. Among Black patients with NSCLC, 15.7% had used ICIs within 2 years of diagnosis, compared to 18% of their White counterparts. Conclusions This population-based study documented significant rural-urban and racial disparities in ICI uptake and time to ICI treatment. Further investigations to identify the sources of rural-urban disparities are warranted, since it is unclear whether the rural-urban ICI uptake gap is due to rural hospital care, or another quality of rural patients. This study emphasizes the need for initiatives improving rural and Black access to ICI treatment. Decades-old disparities in rural and Black patient care persist even as NSCLC treatments improve. A crucial step in improving NSCLC outcomes is ensuring everyone can access the best quality of care. In today’s landscape, that means accessing ICIs. Citation Format: Mary T. Davis, Nikita Nikita, Krupa Gandhi, Scott W. Keith, Rebecca Hartmann, Amy Shaver, Swapnil Sharma, Grace Lu-Yao. Urban-rural and racial disparities in the uptake of Immune Checkpoint Inhibitor (ICI) treatments for non-small cell lung cancer (NSCLC) – A population-based study abstract. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr B161.