ASPO Abstracts
Association of county-level social context and county-level, subtype-specific breast cancer incidence among Black and White women
Category: Cancer Health Disparities
Conference Year: 2023
Abstract Body:
Purpose: To assess the association of county-level social context with county-level incidence rates of HR/HER2 (hormone receptor/human epidermal growth factor receptor 2) breast cancer subtype among Black and White women Methods: To model county-level social context, we applied exploratory factor analysis to Health Inequality Project data; 2,840 U.S. counties had complete data on 22 variables of interest. Next, we linked the factor data to 2010-2017 Surveillance, Epidemiology, and End Results program county-level, age-adjusted breast cancer incidence rates for females age ≥50 years at diagnosis. To determine the association of each social context factor with breast cancer incidence, we performed multivariable linear regression to estimate effect sizes (β) and P values. Final analyses (N=996 counties) were stratified by breast cancer subtype (HR+/HER2+, HR-/HER2+, HR+/HER2-, HR-/HER2-) and race (Black, White). Results: We identified a five-factor model of social context: 1) racial and economic segregation, 2) population change, 3) generational dispossession, 4) economic environment, and 5) population and housing. Compared to counties in the first tertile, counties in the third (or highest) tertile of generational dispossession had significantly greater county-level Black breast cancer incidence rates across all subtypes; the strongest association was for HR+/HER2- breast cancer (β=56.7, P=0.02). Better economic environment was associated with lower Black HR-/HER2- breast cancer incidence (third tertile: β= -26.8, P=0.02). Similar associations of smaller magnitude were observed for county-level White incidence rates (generational dispossession third tertile: HR+/HER2- β=16.3, P<0.01; economic environment third tertile: HR-/HER2- β= -5.2, P<0.001). Additionally, counties in the third tertile of racial and economic segregation had lower White HR-/HER2- (β= -2.4, P=0.04) and higher HR+/HER2- (β= 11.9, P<0.001) breast cancer incidence rates, whereas there was no significant association among Black women. Conclusions: County-level social context was associated with county-level, subtype-specific breast cancer incidence, and associations differed by race. These preliminary findings may inform biosocial studies of breast cancer incidence among Black and White women.
Keywords: social context, breast cancer disparities, exploratory factor analysis