Abstract C070: Social determinants of health disparities in triple-negative breast cancer in Louisiana

Abstract

Abstract Introduction: Triple-negative breast cancer (TNBC) is an aggressive, heterogeneous subtype of breast cancer. TNBC patients have generally high risk of recurrence and metastasis, and treatment options remain limited, as there are no effective targeted therapies available. In USA, TNBC is diagnosed disproportionately more frequently in African American (AA) women than in European American (EA) women. We set out to investigate the role of social determinants in racial disparities in TNBC. Methods: TNBC patients diagnosed in Louisiana from 2010-2012 were identified from the Louisiana Tumor Registry. Patients were geocoded to census tract of residence at time of diagnosis. Census tract population and socioeconomic measures were obtained from the US Census American Community Survey. We used multilevel statistical models to analyze the role of neighborhood concentrated disadvantage index (CDI), a robust measure of physical and social environment, in racial disparities in TNBC incidence, stage at diagnosis, and stage-specific survival for the study population. CDI scores were calculated according to the PhenX Toolkit protocol. Results: We identified 1,216 women with TNBC for the study. Controlling for age, we found that AA women had a 2.21-fold risk of TNBC incidence compared to EA in Louisiana. Results from multivariate analyses indicated that the incidence of TNBC was independent of neighborhood CDI, as was the racial disparity. However, CDI did explain existing racial disparities in both stage at diagnosis and stage-specific survival. The odds of diagnosis at later stages were 42% higher for black women. A single standard deviation increase in CDI increased the hazard of breast cancer-related death by 19%. Overall, our results suggest that the increased incidence of TNBC in black women is independent of CDI, while neighborhood environment has a greater impact than race on the promotion and progression of the disease. The socioeconomic disadvantage experienced by black women coupled with increased biologic risk for TNBC contribute to the large racial disparity in breast cancer mortality in Louisiana. Further research is needed to determine the mechanisms through which social determinants affect the promotion and progression of this disease and guide efforts to improve overall survival. Citation Format: Fokhrul Hossain, Denise Danos, Aubrey Gilliland, Claudia Leonardi, Tekeda Ferguson, Neal Simonsen, Qingzhao Yu, Om Prakesh, Richard Scribner, Lucio Miele. Social determinants of health disparities in triple-negative breast cancer in Louisiana [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C070.