Improving our understanding of breast cancer mortality disparities through recurrence: a multi-level approach among women in Georgia

PROJECT SUMMARY/ABSTRACT Significance. Although efforts to improve breast cancer prognosis through advancements in early detection and treatment have led to declines in breast cancer mortality rates, racial disparities in breast cancer mortality still exist, where Black women are 40% more likely to die from breast cancer than White women. Reasons for

this disparity are not completely understood. Racial differences in the development of aggressive breast tumors likely contribute to the disparity, but little is known about causal drivers of aggressive disease. Social and environmental factors, such as the neighborhood environment, have been posited as potential contributors

to breast cancer disparities, but their role in observed racial disparities is not clear. The proposed research seeks to identify potential drivers of the observed breast cancer racial disparities by investigating the impact of neighborhood environment on breast cancer mortality and the development of aggressive tumor types.

Innovation. This proposal is innovative in that it will examine three neighborhood deprivation composite measures to determine whether differences in exposure assessment contribute to inconsistent results in prior literature, explore joint effects of neighborhood deprivation, race, and other neighborhood features, such as

rurality, to identify subpopulations of Black and White women who may be particularly vulnerable to poor breast cancer outcomes, and identify causal drivers of triple-negative breast cancer. Approach. Using census data to derive each composite measure and data on ~30,000 women diagnosed with invasive stage I-IIIA breast

cancer in Georgia and followed for up to 13-years, we will estimate the association between neighborhood deprivation and breast cancer mortality, exploring both stratum-specific and joint effects of race and other area characteristics. We will also assess neighborhood deprivation in relation to the development of triple-negative

breast cancer vs. other breast cancer subtypes. Impact. This research will enhance our understanding of how the neighborhood environment influences breast carcinogenesis, particularly among Black women, who are more likely to live in deprived neighborhoods, develop triple-negative breast cancer, and experience worse

breast cancer outcomes of any racial or ethnic group. This research will also advance the scientific strategy of the parent study (R01CA259192), by informing its multi-level modeling approach to identify proximal, intermediate, and distal determinants of disparities in breast cancer recurrence and mortality, and ultimately

provide clarity on the role of neighborhoods in driving breast cancer disparities. Moreover, execution of the proposed research could inform future multi-level interventions that can be implemented at the community level to reduce these disparities.