Abstract PO-005: Where you live matters: Impact of economic, racial/ethnic, and racialized economic residential segregation on breast cancer survival
Authors: Goel Neha , Yadegarynia Sina , Kelly Kristin N. , Kesmodel Susan B. , Kobetz Erin N. , Westrick Ashly 
Published: December 2020

Abstract
Background Racial and economic residential segregation remains a problem within the United States (US). Although advances in screening, detection, diagnosis, and treatment have reduced overall breast cancer mortality, well-documented socioeconomic and racial/ethnic survival disparities persist. The objective of this study was to analyze the effect of economic and racial/ethnic residential segregation, as measured by the Index of Concentration at the Extremes (ICE), on breast cancer survival. Methods Patients treated at our medical campus, comprised of a safety-net hospital and an academic cancer center, with stage I-IV breast cancer from 2005-2017 were identified from our tumor registry. Census tracts were used as neighborhood proxies. Using 5-year estimates from the American Community Survey, 5 ICE variables were computed: economic (high vs. low), race/ethnicity (non- Hispanic White (NHW) vs. non-Hispanic Black (NHB) and NHW vs. Hispanic) and racialized economic (low-income NHB vs high-income NHW and low-income Hispanics vs. high-income NHW) segregation. ICE uniquely captures spatial economic and racial/ethnic segregation by mapping social inequality not otherwise captured by evaluating a population of a specific socioeconomic level or belonging to a particular racial/ethnic group. Random effects frailty models were conducted for all patients and then stratified by race/ethnicity controlling for demographics, tumor characteristics, and NCCN-guideline appropriate treatment subtype. Results The study population included 6,145 breast cancer patients. 52.6% were Hispanic, 26.3% were NHW, and 17.2% were NHB. After controlling for multiple covariates, those living in extreme economically disadvantaged neighborhoods had an increased hazard ratio (HR) of death compared to those living in more economically advantaged neighborhoods (HR: 1.58 95% CI: 1.29-1.92, p&lt;0.001). Patients living in an economically disadvantaged NHB neighborhood also had an increased HR compared to those living in more economically advantaged NHW neighborhoods (HR: 2.0 95% CI:1.54-2.60, p&lt;0.001). In race-stratified analyses, a NHW living in an economically disadvantaged NHB neighborhood had an increased HR compared to a NHW living in an economically advantaged NHW neighborhood (HR: 2.02 95% CI:1.19-3.41, p&lt; 0.0071), even when controlling for demographics, tumor subtype, and appropriate treatment. Conclusion This study is the first to evaluate breast cancer survival by ICE, which brings social inequality to the forefront. Our study suggests that survival disparities persist at the extremes of economic deprivation/privilege and racial/ethnic residential segregation, even when accounting for demographics, tumor characteristics, and appropriate treatment, suggesting social/environmental factors are also impacting survival. To address these disparities, effective interventions are needed that account for the social and environmental contexts in which cancer patients live and are treated.
Citation Format: Neha Goel, Sina Yadegarynia, Kristin N. Kelly, Susan B. Kesmodel, Erin N. Kobetz, Ashly Westrick. Where you live matters: Impact of economic, racial/ethnic, and racialized economic residential segregation on breast cancer survival [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-005.