Racial disparities in breast cancer mortality in a multiethnic cohort in the Southeast.

BACKGROUND: Although much has been done to examine those factors associated with higher mortality among African American women, there is a paucity of literature that examines disparities among rural African Americans in South Carolina. The purpose of this investigation was to examine the association of race and mortality among breast cancer patients in a large cohort residing in South Carolina for which treatment regimens are standardized for all patients.
METHODS: Subjects included 1209 women diagnosed with breast cancer between 2000 and 2002 at a large, local hospital containing a comprehensive breast center. Kaplan-Meier survival curves were calculated to determine survival rates among African American and European American women, stratified by disease stage or other prognostic characteristics. Adjusting for various characteristics, Cox multivariate survival models were used to estimate the hazard ratio (HR).
RESULTS: The 5-year overall all-cause mortality survival proportion was ∼78% for African American women and ∼89% for European American women, P < 0.01. In analyses of subpopulations of women with identical disease characteristics, African American women had significantly higher mortality than European American women for the same type of breast cancer disease. In multivariate models, African American women had significantly higher mortality than European American women for both breast cancer-specific death (HR, 2.41; 95% confidence interval [CI], 1.21-4.79) and all-cause mortality (HR, 1.42; 95% CI, 1.06-1.89).
CONCLUSIONS: African American women residing in rural South Carolina had lower survival for breast cancer even after adjustment for disease-related prognostic characteristics. These findings support health interventions among African American breast cancer patients aimed at tertiary prevention strategies or further down-staging of disease at diagnosis.