Risk Factors for Fatal Breast Cancer in African-American Women and White Women in a Large US Prospective Cohort

Abstract

African-American women have a higher lifetime risk of fatal breast cancer than do White women. Recent studies suggest that breast cancer risk factors may vary by race. The authors examined risk factors for fatal breast cancer in postmenopausal African-American women and White women in a large US prospective cohort. In 1982, 21,143 African-American women and 409,093 White women in the Cancer Prevention Study II completed a questionnaire on reproductive, medical, anthropometric, and demographic factors. During a 20-year follow-up, 257 deaths from breast cancer occurred among African-American women and 4,265 among Whites. Cox proportional hazards modeling was used to calculate multivariate-adjusted rate ratios, stratified by race. Higher body mass index, taller height, and physical inactivity were associated with increased breast cancer mortality rates in both groups. A college education was associated with higher mortality from breast cancer only in Africa-American women (hazard ratio = 1.62, 95% confidence interval: 1.13, 2.30; p(trend) = 0.01, vs. less than a high school education). Most other risk factors were associated with breast cancer rates similarly in both groups. With few exceptions, established breast cancer risk factors were similarly associated with risk of death from breast cancer among African-American women and White women.