Rural-urban survival differences in advanced non–small cell lung cancer in the modern treatment era: A SEER-based analysis.

Abstract

e13735 Background: Rural-urban disparities in cancer outcomes are well documented; however, whether recent therapeutic advances have translated into equitable survival gains for patients with advanced non-small cell lung cancer (NSCLC) remains unclear. Beginning 2015, immune checkpoint inhibitors became standard for advanced NSCLC. This study examined rural-urban differences in overall survival (OS) across treatment eras. Methods: Data were obtained from the SEER 17 database and included adults with distant-stage NSCLC. Patients were classified as rural or urban and stratified by era of diagnosis (pre-2015 vs post-2015). OS was analyzed using Kaplan–Meier methods and compared using the log-rank test. Multivariable Cox proportional hazards models adjusted for age, sex, race, income, and marital status, and included an interaction term between rural residence and era of diagnosis. Results: A total of 248,598 adults were identified; 14.8% resided in rural areas and 85.2% in urban areas. Overall, 59.3% were diagnosed in the pre-2015 era and 40.7% in the post-2015 era. The population was predominantly male and aged ≥65 years, with a median OS (mOS) of 6 months. Patients in rural areas had inferior OS compared with urban residents (mOS 5 vs 6 months; P < 0.001). On multivariable analysis, rural residence was independently associated with increased mortality. Increasing age, male sex, Black race, lower household income, and single or previously married status were also associated with higher mortality (Table 1). In era-stratified analyses, rural-urban survival differences persisted and widened after 2015. In the pre-2015 era, mOS was 5 months in both groups (P < 0.001). In the post-2015 era, mOS increased to 7 months in urban patients but remained 5 months in rural patients (P < 0.001). In interaction-adjusted analysis, post-2015 diagnosis was associated with reduced mortality overall, while rural patients experienced an additional mortality risk in the post-2015 era. Conclusions: Among adults with distant-stage NSCLC, rural residence was associated with inferior overall survival compared with urban residence. Survival gains after 2015 were primarily observed in urban patients, resulting in widening rural-urban disparities. These findings highlight geographic inequities in advanced lung cancer outcomes and the need to improve access to cancer care for rural populations. Multivariate analysis. Variable Hazard Ratio (HR) 95% CI P value Rural (vs Urban) 1.04 1.03–1.06 <0.001 Post-2015 (vs Pre-2015) 0.79 0.78–0.80 <0.001 Rural × Post-2015 interaction 1.04 1.02–1.07 <0.001 Age (per year) 1.02 1.02–1.02 <0.001 Male (vs Female) 1.25 1.24–1.26 <0.001 Black (vs White) 1.04 1.02–1.06 <0.001 Asian (vs White) 0.81 0.79–0.83 <0.001 ≥$75,000 (vs <$75,000) 0.93 0.92–0.93 <0.001 Single (vs Married) 1.25 1.24–1.27 <0.001 Previously married (vs Married) 1.18 1.17–1.19 <0.001