A nearly 20-year observational study involving more than 44,700 black women nationwide found that regular vigorous exercise offers significant protection against development of an aggressive subtype of breast cancer. The findings from the Black Women’s Health Study were presented at the 2013 San Antonio Breast Cancer Symposium, December 10-14, 2013.
The research team, co-led by scientists at Georgetown Lombardi Comprehensive Cancer Center in Washington, DC, and Boston University in Massachusetts, found that black women who engaged in brisk exercise for a lifetime average of 3 or more hours a week had a 47% reduced risk of developing estrogen receptor (ER)-negative breast cancer compared with those exercising an average of 1 hour per week, according to a preliminary analysis. The study included 44,704 women age 30 years or older.
This form of breast cancer, which includes human epidermal growth factor receptor 2 (HER2)-positive and triple-negative tumors, is linked to both higher incidence and mortality in black women, relative to white women. ER-negative tumors do not respond to hormone therapies used to treat tumors that have the estrogen receptor.
“These findings are very encouraging. Knowing that exercise may protect against breast cancers that disproportionately strike black women is of great public health importance,” said Lucile Adams-Campbell, PhD, professor of oncology and associate director of Minority Health & Health Disparities Research at Georgetown Lombardi.
“We all want to do what we can to reduce our risk of disease and improve our health, and along with other well-known benefits, we now show that exercise can possibly stave off development of potentially lethal breast cancer in black women,” she said.
Exercise, at any level, appeared to have no effect on development of ER-positive breast cancer in these women, the researchers said. They cannot offer a reason why because their study was not designed to answer this question. They also cannot speculate on whether vigorous exercise in white women would have any effect.