Since the 1970s, overall age-adjusted breast cancer mortality rates in the U.S.have been higher among African American (AA) women than among Caucasian American (CA) women. The racial disparity is not fully explainable based on socioeconomic factors. Suspected biologic factors underlying this trend may be interpreted by both epidemiologic and clinical perspectives. Descriptive epidemiologic studies suggest that breast cancer may be a mixture of at least 2 main diseases and/or causal pathways. The first breast cancer is early-onset, with peak incidence near age 50 years and generally more aggressive outcome. The second breast cancer is late-onset, with peak incidence near age 70 years and more indo- KEYWORDS: breast cancer, racial traits, African American, Caucasian American, host-tumor interaction.P opulation-based statistics in the U.S. indicate that overall ageadjusted breast cancer mortality rates are higher among African American women (AA) than among Caucasian American women (CA), and the disparity is increasing.1 There is a mortality disadvantage of between 1.5-fold to 2.2-fold that first appeared in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) data in the mid-1970s and has been widening ever since.
2,3The differential access to medical care and screening and even disparities in disease management (diagnostic procedures, treatment decisions, etc) are usually considered the source of the different race-related outcomes. A recent review on this issue, 4 addressing the role of patient-, provider-, and health system-level factors and discussing practical approaches to optimize them to