Higher population-based incidence rates of triple-negative breast cancer among young African-American women : Implications for breast cancer screening recommendations.

BACKGROUND: Differences in the breast cancer burden of African-American women compared with white American women are well documented. Recent controversies have emerged regarding age-appropriate mammographic screening guidelines, and these surveillance recommendations may influence future breast cancer disparities. The objective of the current study was to evaluate age-specific breast cancer stage distributions and incidence rates of triple-negative breast cancer (TNBC) in a population-based tumor registry.
METHODS: The authors analyzed breast cancers from the California Cancer Registry (CCR) that were diagnosed between 1988 and 2006. The results were stratified by age and race/ethnicity, with white Americans identified as non-Hispanic whites (NHWs) and African Americans identified as non-Hispanic blacks (NHBs). Breast cancer stage distributions and TNBC incidence rates also were analyzed.
RESULTS: In total, 375,761 invasive breast cancers were evaluated (including 276,938 in NHWs and 21,681 in NHBs). NHBs and Hispanics tended to be younger than NHWs (median ages 57 years, 54 years, and 64 years, respectively). Lifetime incidence rates were higher for NHWs compared with NHBs and Hispanics; however, for women aged <44 years, incidence was highest among NHBs. NHBs also had higher incidence rates of stage III and IV disease and a higher incidence of TNBC in all age categories.
CONCLUSIONS: Population-based data demonstrated that African-American women had a more advanced stage distribution for breast cancer compared with white American women and higher incidence rates for TNBC. These patterns were observed for women ages 40 to 49 years and for older women, and they suggest that mammographic screening for the early detection of breast cancer will be particularly relevant for younger African-American women.