Racialized Economic Segregation and Treatment and Outcomes of Small Cell Lung Cancer

Background: Little is known about the role of residential segregation in the treatment and outcomes of small cell lung cancer (SCLC), a highly recalcitrant disease, among non-Hispanic White (NHW) and non-Hispanic Black (NHB) patients. Methods: We used the Surveillance, Epidemiology, and End Results database to identify men and women diagnosed with SCLC from January 2007 to December 2015 (n = 38,393). An Index of Concentration at the Extremes was computed to measure county-level racialized economic segregation and categorized into Quartile 1 (most privileged: highest concentration of high-income NHW residents) through Quartile 4 (least privileged: highest concentration of low-income NHB residents). Multilevel logistic regression was used to estimate the ORs for extensive-stage diagnosis and nonadherence to guideline-recommended treatment. HRs for lung cancer–specific and overall mortalities were computed using multilevel Cox regression. Results: Patients in the least privileged counties had higher risks of nonadherence to guideline-recommended treatment [OR = 1.23; 95% confidence interval (CI): 1.08–1.40; P_trend < 0.01], lung cancer–specific mortality (HR = 1.08; 95% CI: 1.04–1.12; P_trend < 0.01), and all-cause mortality (HR = 1.13; 95% CI: 1.09–1.17; P_trend < 0.0001) compared with patients in the most privileged counties. Adjustment for treatment did not significantly reduce the association with mortality. These associations were comparable between NHB and NHW patients. Segregation was not significantly associated with extensive-stage diagnosis. Conclusions: The results suggest that living in the neighborhoods with higher proportions of low-income households and Black residents had adverse impacts on stage-appropriate treatment of and survival from SCLC. Impact: This highlights the need for improving the access to quality lung cancer care in the less privileged neighborhoods.