Abstract A037: Understanding the role of neighborhood deprivation in racial and urban-rural disparities in triple negative breast cancer
Authors: Barber Lauren E. , Miller-Kleinhenz Jasmine M. , Maliniak Maret L. , Moubadder Leah , Switchenko Jeffrey M. , McCullough Lauren E. 
Published: September 2024

Abstract
Background: Triple negative breast cancer (TNBC) accounts for 15% of all breast cancers and is one of the most aggressive disease subtypes. Disparities in TNBC exist, where US Black women and women living in urban environments are more likely to be diagnosed with TNBC than their White or rural counterparts. Reasons for these disparities are not completely understood. Social determinants of health, such as the neighborhood environment, have been implicated as potential contributors to breast cancer disparities. To improve our understanding of disparities in TNBC, we examined neighborhood deprivation in relation to breast cancer subtype, according to race and rurality. Methods: We identified 40,095 non-Hispanic Black and White women diagnosed with invasive breast cancer in 2010-2017 in the Georgia Cancer Registry. Neighborhood deprivation was measured by the Neighborhood Deprivation Index (NDI), a composite measure of neighborhood poverty, income, housing, unemployment, occupation, and education derived through principal component analysis using 2011-2015 block group-level American Community Survey data. Georgia Department of Public Health data were used to measure county-level rurality. We estimated case-only multivariable odds ratios (OR) and 95% confidence intervals (CI) for the separate associations between NDI, in quintiles, and each breast cancer subtype (TNBC, ERBB2+, or luminal B vs. luminal A breast cancer), overall and according to race and rurality. Results: Of the 40,095 non-Hispanic Black (31.5%) and White (68.5%) women, 5,328 were diagnosed with TNBC, 1,926 with ERBB2+, 4,958 with luminal B, and 27,883 with luminal A breast cancer. Compared to living in the least deprived neighborhoods, living in the most deprived neighborhoods was associated with a 33% (OR= 1.33, 95% CI 1.19-1.48) increased odds of TNBC vs. luminal A breast cancer. Race and rurality did not modify the association. However, estimates were less pronounced among non-Hispanic Black (OR=1.18, 95% CI 1.00-1.39) compared to non-Hispanic White (OR=1.40, 95% CI 1.18- 1.65) women and among women living in urban (OR=1.33, 95% CI 1.18-1.50) compared to rural (OR=1.52, 95% CI 1.15-2.03) counties. Neighborhood deprivation was associated with an increase in ERBB2+ breast cancer (OR=1.19, 95% CI 1.00-1.40), which was confined to non- Hispanic White women (OR=1.29, 95% CI 1.00-1.66) and women living in urban counties (OR=1.25, 95% CI 1.04-1.52). The OR for luminal B breast cancer was 1.08 (95% CI 0.96- 1.21). Although race did not modify this relationship, an association was observed only among women living in urban counties (OR=1.14, 95% CI 1.00-1.29). Conclusions: In this population of Georgia breast cancer patients, neighborhood deprivation was associated with an increase in TNBC, regardless of race or rurality. The weaker associations among non-Hispanic Black women and women living in urban counties suggests that other factors, in addition to neighborhood deprivation, may play an important role in TNBC development among Black women and women residing in urban environments.
Citation Format: Lauren E. Barber, Jasmine M. Miller-Kleinhenz, Maret L. Maliniak, Leah Moubadder, Jeffrey M. Switchenko, Lauren E. McCullough. Understanding the role of neighborhood deprivation in racial and urban-rural disparities in triple negative breast cancer [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A037.