Abstract 4202: Identifying predictors of racial disparities in mortality among Blacks and Whites diagnosed with breast cancer in South Carolina

Introduction: Mortality among White breast cancer (BrCA) patients is 7% lower in South Carolina (SC) and is 29% higher among Black BrCA patients in SC compared to the national average. The aim of this study was to identify predictors of racial disparities in mortality among Black and White BrCA patients in SC. Methods: Breast cancer cases were obtained retrospectively from the SC Central Cancer Registry, linked with administrative data from a private payor insurance and Medicaid Plan from 2002 to 2010. The main outcome variable was mortality which was operationalized by vital status and total survival time. The main exposure variable was patient race (White vs Black). Cox proportional hazard analyses were conducted to compare hazard ratios among Blacks and Whites to identify predictors of mortality. In assessing the relationship between race and mortality, we examined marital status, urbanicity, region, and Best Chance Network enrollment as potential effect modifiers. The multivariable model was stratified by the effect modifier variables and a backward elimination process was utilized to obtain the best fitting model among models with the following covariates: age, year of diagnosis, hormone-receptor status, stage, and grade. Results: A total of 2155 breast cancer patients (nWhites=1557; nBlacks= 598) were reported in the study period. Adjusting for cancer stage, the hazard ratio of mortality was 3.45 (1.64,7.25) among Black women who lived in the Low Country region of the state compared with White women who lived in the Low Country region of the state. In the other three regions of the state (Midlands, PeeDee and Upstate); there were no statistically significant differences between Blacks with Whites. Adjusting for cancer stage and grade showed that the hazard ratio of mortality was 1.53 (1.04,2.26) among Black women who lived in urban areas compared with White women who lived in urban areas. There were no differences between Blacks and Whites who lived in rural areas. Conclusions: Mortality was higher among Blacks who lived in the Low Country region of the state and among Blacks who lived in urban areas. To reduce racial disparities in survival, efforts directed at early detection and linkage to timely breast cancer treatment should be focused on black women living in the Low Country region of the state and in urban areas. Citation Format: Oluwole Adeyemi Babatunde, Swann A. Adams, Jan M. Eberth, Tisha M. Felder, Robert Moran, Samantha Truman, Christian Alvarado, James Hebert. Identifying predictors of racial disparities in mortality among Blacks and Whites diagnosed with breast cancer in South Carolina [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4202.