A new study provides evidence that African-American women who breast-feed have a lower risk of being diagnosed with estrogen receptor-negative and triple-negative breast cancer. In the study Parity, Lactation, and Breast Cancer Subtypes in African American Women: Results from the AMBER Consortium, researchers analyzed data from 2,446 cases of ER-positive cancer, 1,252 cases of ER-negative cancer and 567 cases of triple-negative cancer, among African-American women, as well as more than 14,000 control patients. The results suggested African-American women who had given birth but did not breast-feed had an increased risk of ER-negative and triple-negative breast cancer.
The study found that African-American women who had given birth had a 33% higher risk of ER-negative breast cancer and a 37% higher risk of triple-negative breast cancer compared with women who had never given birth. However, the women who breast-fed reduced their risk of ER-negative breast cancer, but not ER-positive breast cancer. The risk of ER-negative breast cancer increased with each additional birth in women who did not breast-feed.
The findings suggest that parous women who have not breast-fed are at increased risk of ER- and triple-negative breast cancer, the studys researchers wrote. Promotion of lactation may be an effective tool for reducing occurrence of the subtypes that contribute disproportionately to breast cancer mortality.
The study, published in the Journal of the National Cancer Institute, was conducted by the African American Breast Cancer Epidemiology and Risk Consortium.
Read the abstract: http://jnci.oxfordjournals.org/content/106/10/dju237.abstract