Racial Disparities in Breast Cancer Survival: An Analysis by Age and Stage

Background. Black women often present with advanced-stage breast cancer compared with White women, which may result in the observed higher mortality among Black women. Age-related factors (e.g., comorbidity) also affect mortality. Whether racial disparities in mortality are evident within age and/or stage groups hits not been reported, and risk factors for greater mortality among Black women are not well defined. Methods. Using the 1988-2003 Surveillance, Epidemiology, and End Results Program data, we conducted a retrospective, population-based cohort study to compare overall and stage-specific breast-cancer mortality between Black and White women within each age (<40,40-49,50-64, and 65+) and stage (stage 0-IV and unstaged) group at diagnosis. Cox: regression models calculated unadjusted and adjusted hazard ratios (HR) and 95% confidence intervals (CI), the latter controlling for potential confounders of the relationship between race and survival. Results. In the 1988-2003 Surveillance, Epidemiology, and End Results data, 20,424: Black and 204,506 White women were diagnosed with first primary breast cancer. In unadjusted models, Black women were more likely than White women to die from breast cancer (HR: 1.90; 95% CI: 1.83-1.96) and from all causes (HR: 1.52; 95% CI: 1.48-1.55) during follow-up. In models stratified by age and stage, Black women were at increased risk of breast-cancer-specific mortality within each StRge group among women <65 y. Conclusion. Racial disparities in breast-cancer-specific mortality were predominantly observed within each stage at diagnosis among women <65 y old. This greater mortality risk for Black women was largely not observed among women >= 65 y of age. (C) 2009 Elseiver Inc. All rights reserved.