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 in South Florida.

Methods:Patients treated at our medical campus with stage I-IV breast cancer from 2005-2017 were identified from our local 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 captures spatial socioeconmic and racial/ethnic segregation by literally mapping a critical dimension of social inequality not otherwise captured by metrics that characterize areas solely in terms of the proportion of the population at a specified socioeconomic level or identified as belonging to a particular racial/ethnic group. Random effects frailty models were conducted for all patients and then stratified by race/ethnicity controlling for sociodemographics, tumor characteristics, and NCCN-guideline appropriate treatment.

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 a statistically significant increased mortality compared to those living in more economically advantaged neighborhoods (HR: 1.58 95%CI: 1.29, 1.92, p<0.001), Table 1. Patients living in an economically disadvantaged NHB neighborhood also had a statistically significant increased mortality compared to those living in more economically advantaged NHW neighborhoods (HR: 2.0 95% CI: 1.54, 2.60, p<0.001). In race-stratified analyses, an NHW person living in a predominantly economically disadvantaged NHB neighborhood had increased mortality compared to a NHW person living in an economically advantaged NHW neighborhood (HR: 2.02 95%CI: 1.19-3.41, p< 0.0071) controlling for tumor subtype and NCCN-guideline appropriate treatment.

Conclusion:This is the first study to evaluate breast cancer survival by ICE, which identifies inequitable associations by conveying extreme concentrations of both economic deprivation/privilege and racial/ethnic segregation. Our study suggests that breast cancer survival disparities is partly influenced by extreme racial/ethnic and economic segregation. Even when accounting for sociodemographics, tumor characteristics, and NCCN-guideline appropriate treatment, survival disparities remained, suggesting potential social and environmental factors 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.

Table 1: Breast Cancer Hazard Ratio by Economic, Racial/Ethnic, and Racialized Economic Residential Segregation Residential Segregation

Type of Segregation (ICE)QuartileModel 1Model 2Model3
HR (95% CI)HR (95% CI)HR (95% CI)
Economic Segregation Q1 1.83 (1.1, 3.03)* 1.64 (0.89, 3.02) 1.58 (1.29, 1.92)* 
Economic Segregation Q2 2.36 (1.48, 3.76)* 2.45 (1.38, 4.34)* 1.44 (1.16, 1.79)* 
Economic Segregation Q3 1.16 (0.72, 1.8) 1.08 (0.61, 1.9) 1.16 (0.94, 1.44) 
Economic Segregation Q4 
NHB Segregation Q1 1.6 (0.9, 2.84) 1.42 (0.72, 2.82) 1.41 (0.96, 2.07) 
NHB Segregation Q2 0.92 (0.52, 1.6) 0.91 (0.47, 1.77) 1 (0.68, 1.48) 
NHB Segregation Q3 0.61 (0.29, 1.26) 0.85 (0.37, 1.94) 0.82 (0.52, 1.31) 
NHB Segregation Q4 
Hispanic Segregation Q1 1.38 (0.83, 2.28) 1.13 (0.61, 2.08) 1.36 (1.12, 1.66)* 
Hispanic Segregation Q2 79 (0.47, 1.32) 0.74 (0.4, 1.38) 0.86 (0.67, 1.08) 
Hispanic Segregation Q3 0.94 (0.59, 1.49) 0.98 (0.57, 1.67) 1.05 (0.86, 1.29) 
Hispanic Segregation Q4 
NHB Economic Segregation Q1 2.68 (1.6, 4.47)* 2.02 (1.09, 3.74) 2 (1.54, 2.6)* 
NHB Economic Segregation Q2 1.85 (1.15, 2.97)* 1.39 (0.79, 2.44) 1.56 (1.22, 2.02)* 
NHB Economic Segregation Q3 1.2 (0.69, 2.07) 1.09 (0.58, 2.06) 1.19 (0.88, 1.6) 
NHB Economic Segregation Q4 
Hispanic Economic Segregation Q1 1.91 (1.19, 3.07)* 1.45 (0.83, 2.54) 1.64 (1.24, 2.15)* 
Hispanic Economic Segregation Q2 1.45 (0.8, 2.62) 1.06 (0.52, 2.17) 1.44 (1.06, 1.96)* 
Hispanic Economic Segregation Q3 1.26 (1.73, 2.18) 0.95 (0.49, 1.84) 1.11 (0.8, 1.54) 
Hispanic Economic Segregation Q4 
Model 1: Adjusted for ICE, race/ethnicity, age, insurance  
Model 2: Adjusted for Model 1 covariates plus receptor status, clinical stage 
Model 3: Adjusted for Model 1 and 2 covariates plus stage appropriate treatment 
Q1: Most disadvantaged neighborhoods; Q4: Reference: most advantaged neighborhoods.*p < 0.05 
Type of Segregation (ICE)QuartileModel 1Model 2Model3
HR (95% CI)HR (95% CI)HR (95% CI)
Economic Segregation Q1 1.83 (1.1, 3.03)* 1.64 (0.89, 3.02) 1.58 (1.29, 1.92)* 
Economic Segregation Q2 2.36 (1.48, 3.76)* 2.45 (1.38, 4.34)* 1.44 (1.16, 1.79)* 
Economic Segregation Q3 1.16 (0.72, 1.8) 1.08 (0.61, 1.9) 1.16 (0.94, 1.44) 
Economic Segregation Q4 
NHB Segregation Q1 1.6 (0.9, 2.84) 1.42 (0.72, 2.82) 1.41 (0.96, 2.07) 
NHB Segregation Q2 0.92 (0.52, 1.6) 0.91 (0.47, 1.77) 1 (0.68, 1.48) 
NHB Segregation Q3 0.61 (0.29, 1.26) 0.85 (0.37, 1.94) 0.82 (0.52, 1.31) 
NHB Segregation Q4 
Hispanic Segregation Q1 1.38 (0.83, 2.28) 1.13 (0.61, 2.08) 1.36 (1.12, 1.66)* 
Hispanic Segregation Q2 79 (0.47, 1.32) 0.74 (0.4, 1.38) 0.86 (0.67, 1.08) 
Hispanic Segregation Q3 0.94 (0.59, 1.49) 0.98 (0.57, 1.67) 1.05 (0.86, 1.29) 
Hispanic Segregation Q4 
NHB Economic Segregation Q1 2.68 (1.6, 4.47)* 2.02 (1.09, 3.74) 2 (1.54, 2.6)* 
NHB Economic Segregation Q2 1.85 (1.15, 2.97)* 1.39 (0.79, 2.44) 1.56 (1.22, 2.02)* 
NHB Economic Segregation Q3 1.2 (0.69, 2.07) 1.09 (0.58, 2.06) 1.19 (0.88, 1.6) 
NHB Economic Segregation Q4 
Hispanic Economic Segregation Q1 1.91 (1.19, 3.07)* 1.45 (0.83, 2.54) 1.64 (1.24, 2.15)* 
Hispanic Economic Segregation Q2 1.45 (0.8, 2.62) 1.06 (0.52, 2.17) 1.44 (1.06, 1.96)* 
Hispanic Economic Segregation Q3 1.26 (1.73, 2.18) 0.95 (0.49, 1.84) 1.11 (0.8, 1.54) 
Hispanic Economic Segregation Q4 
Model 1: Adjusted for ICE, race/ethnicity, age, insurance  
Model 2: Adjusted for Model 1 covariates plus receptor status, clinical stage 
Model 3: Adjusted for Model 1 and 2 covariates plus stage appropriate treatment 
Q1: Most disadvantaged neighborhoods; Q4: Reference: most advantaged neighborhoods.*p < 0.05 

Citation Format: Neha Goel, Kristin N Kelly, Sina Yadegarynia, Seraphina Choi, Susan B Kesmodel, 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 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SS1-01.