Abstract 2153: The impact of socioeconomic and racial segregation on cancer stage at diagnosis, treatment and mortality among patients with small cell lung cancer

Abstract Background: Although studies have revealed the adverse impact of residential segregation on early detection, treatment, and survival of non-small cell lung cancer―a predominant type of lung cancers, it remains unknown regarding the role of residential segregation in treatment and outcomes of small cell lung cancer (SCLC) ―a rare type of lung cancer characterized by rapid growth and poor prognosis. Therefore, we examined the associations of racialized socioeconomic segregation with risks of extensive-stage diagnosis, non-adherence to guideline-recommended treatment, and mortality among non-Hispanic White (NHW) and non-Hispanic Black (NHB) patients with SCLC. Methods: This population-based retrospective cohort study included patients who were diagnosed with SCLC as a first primary malignancy at age 20 and older between January 2007 and December 2015, followed through December 2016, and identified from the Surveillance, Epidemiology, and End Results. County-level racialized socioeconomic segregation was measured using the Index of Concentration at the Extremes (ICE). Multilevel logistic regression accounting for county-level clustering was used to estimate odds ratios (ORs) for extensive-stage diagnosis and non-adherence to guideline-recommended treatment. Hazard ratios (HRs) for lung cancer-specific mortality and all-cause mortality were computed using multilevel Cox regression. Results: Among 38, 393 patients, 90. 1% were NHW and 9. 9% were NHB. Patients dwelling in the counties with the highest concentration of low-income NHB households (highest ICE quartile) had higher risks of non-adherence to guideline-recommended treatment (OR=1. 23, 95% CI: 1. 08-1. 40; Ptrend 0. 01), lung cancer-specific mortality (HR=1. 08, 95% CI: 1. 04-1. 12; Ptrend 0. 01), and all-cause mortality (HR=1. 13, 95% CI: 1. 09-1. 17; Ptrend 0. 0001) as compared with patients dwelling in the counties with the highest concentration of high-income NHW households (lowest ICE quartile). These associations were comparable between NHB and NHW patients. Racialized economic segregation was not significantly associated with extensive-stage diagnosis. Conclusions: Residing in the segregated, low-income NHB counties had adverse impacts on stage-appropriate treatment for SCLC and survival outcomes. Future research on the pathway (s) linking residential segregation to SCLC treatment underutilization and poor outcomes is warranted. Citation Format: Bayu B. Bekele, Min Lian, Ying Liu. The impact of socioeconomic and racial segregation on cancer stage at diagnosis, treatment and mortality among patients with small cell lung cancer abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 2153.