A new review finds similarities between the clinical presentation and course of breast cancer in Africans and African-Americans, suggesting that genetic factors may play a significant role in the racial differences encountered in the epidemiology of breast cancer in America.
The article, published in the April 15, 2005 issue of CANCER, a peer-reviewed journal of the American Cancer Society, also observes that Africa faces potential increases in breast cancer rates as African women adopt Western reproductive and dietary behaviors that have been shown to increase the risk of breast cancer.
Population studies show while African American women have lower rates of breast cancer than white women in the United States, they have poorer outcomes. African American women are also more likely to get breast cancer at a younger age, and among women in the U.S. under the age of 45, African Americans have the highest incidence rates. African Americans are also more likely to be diagnosed with higher stage disease – i.e., estrogen receptor-negative, high-grade tumors that are node-positive. This clinical pattern is similar to that identified in the Ashkenazi populations that led to the discovery of BRCA-1 and -2 gene mutations, prompting many scientists to speculate that there may also be a genetic component contributing to breast cancer in African Americans.
Alero Fregene, M.D. and Lisa A. Newman, M.D., M.P.H. of the University of Michigan Comprehensive Cancer Center conducted an extensive literature review of English-language studies of breast cancer in sub-Saharan Africa. They say understanding the breast cancer burden and clinical characteristics in sub-Saharan Africa, where the majority of African American trace their ancestry from, may contribute to the understanding of racial factors in breast cancer.