RESEARCHERS IDENTIFY POSSIBLE CONTRIBUTORS TO THE HIGHER INCIDENCE OF AGGRESSIVE BREAST CANCERS IN AFRICAN AMERICAN WOMEN
(Boston) – Investigators from the Boston University’s Slone Epidemiology Center have reported findings that may shed light on why African American women have a disproportionately higher risk of developing more aggressive and difficult-to-treat breast cancers, specifically estrogen and progesterone receptor negative (ER-/PR-) cancers.
The study, which appears online in Cancer Epidemiology, Biomarkers & Prevention, found that high parity (giving birth to two or more children) was associated with an increased risk of ER-/PR- cancer, but only among women who had not breastfed.
The findings were based on the ongoing Black Women’s Health Study, which has followed 59,000 African American women by biennial questionnaire since 1995.
In 14 years of follow-up, 318 women developed breast cancers negative for estrogen and progesterone receptors (ER-/PR-), while 457 developed breast cancers with estrogen and progesterone receptors (ER+/PR+). Giving birth to two or more children was associated with a 50 percent increase in the incidence of ER-/PR- breast cancer, but the association was not present among women who had breastfed.
The release also quotes researcher Julie Palmer:
“Our results, taken together with recent results from studies of triple negative and basal-like breast cancer, suggest that breastfeeding can reduce risk of developing the aggressive, difficult-to-treat breast cancers that disproportionately affect African American women,” she said.