Structural racism and breast cancer stage at presentation in a South Florida majority-minority population: a retrospective study

Abstract

Background

Residential segregation, both economic, racial and ethnic, is a social determinant of health that contributes to disparities in breast cancer outcomes. The objective of this study was to examine the association of economic and racial and ethnic residential segregation, as measured by the Index of Concentration at the Extremes (ICE), with breast cancer stage at presentation.

Methods

In this retrospective two-institution study, we included patients with stage I-IV breast cancer from 2005 to 2017. Using five-year estimates from the American Community Survey (2009–2013), five ICE variables were computed to create five models, controlling for economic segregation, Non-Hispanic Black (NHB) segregation, NHB/economic segregation, Hispanic segregation, and Hispanic/economic segregation. Multi-level logistic regression models determined the association between economic and racial segregation on breast cancer stage at presentation.

Findings

4898 patients were included: 56% Hispanic, 27% Non-Hispanic White, 17% NHB. Those living in the most economically marginalised neighbourhoods [by quartiles (Q)] [OR_Q1 1.38 (95% CI: 1.14–1.68), p < 0.05, majority NHB neighbourhoods [OR_Q11.51 (95% CI: 1.01–2.27)], majority Hispanic neighbourhoods [OR_Q1 1.29 (95% CI: 1.06–1.56)], the most NHB and economically segregated neighbourhoods [NHB and economic: OR_Q1 1.64 (95% CI: 1.28–2.09), and the most Hispanic and economically segregated neighbourhoods [Hispanic and economic: OR_Q1 1.60 (95% CI: 1.24–1.68)] had significantly increased odds of presenting with later stage disease compared to the reference group in each category.

Interpretation

This study, to our knowledge, is the first to evaluate stage at presentation by ICE, which allows us to evaluate the association between racial and economic residential segregation and breast cancer disparities. Our findings suggest that structural racism influences stage at presentation. To address these disparities, effective interventions are needed to account for the social and environmental contexts in which cancer patients live and can access care.

Funding

Research reported in this publication was supported by the National Cancer Institute of the National Institutes of Health under Award Number R37CA288502. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The research was also supported by a University of Miami School of Medicine DREAM Scholar Award, a NIH/NCI T32CA211034, an American Surgical Association Fellowship Award, a Breast Cancer Research Foundation, an ASCO Career Development Award, a Florida Department of Health Bankhead Cole Cancer Research Program, a NIH/NCI 5P30 240139-02 Sylvester Cancer Control Support Grant Transdisciplinary Pilot Grant, and a NIH/NCI K12CA226330.