A recent study, published in the current issue of Cancer Epidemiology, Biomarkers & Prevention, found that black women who give birth to at least two children are at a 50% greater risk for hormone receptor-negative breast cancer. Researchers discovered that breast-feeding reduces that risk.
The research was based on the Black Women’s Health Study, which has followed 59,000 African American women since 1995. The study authors analyzed medical information on 457 of the women with hormone receptor-positive breast cancer as well as 318 women who developed hormone receptor-negative breast cancer.
Julie Palmer, professor of epidemiology at the Slone Epidemiology Center at Boston University, stated in a news release from the American Association for Cancer Research that, “African American women are more likely to have had a greater number of full-term births and less likely to have breast-fed their babies. The adverse effect of high childbirth without subsequent breast-feeding seems to be confined to the hormone receptor-negative breast cancer, which carries a higher mortality rate and is more common in African Americans.”
The study also found, by contrast, that higher birth rates among black women decreased a women’s risk for estrogen receptor-positive breast cancer.
For these women, researchers found no link between breast-feeding and their risk for the disease.
Source:Palmer, J. Cancer Epidemiology, Biomarkers & Prevention, September 2011.