Postmenopausal women who consume even moderate amounts of alcohol may face an increased risk of breast cancer

Postmenopausal women who consume even moderate amounts of alcohol may face an increased risk of breast cancer, particularly if their cancer is fueled by the hormones estrogen or progesterone, according to a data analysis by researchers at Boston's Dana-Farber Cancer Institute, Brigham and Women's Hospital, and Harvard School of Public Health.

"Women need to consider the possible effects of alcohol on breast cancer risk when weighing the risks and benefits of alcohol consumption," Chen comments. "Our findings indicate that in some postmenopausal women, even modest levels of alcohol consumption may elevate their risk of breast cancer."

Using data from the Nurses' Health Study - a project led by Boston's Brigham and Women's Hospital that has tracked the health of 122,000 registered nurses since 1976 - Chen and her colleagues focused on breast cancer rates in women who reported drinking small amounts of alcohol (averaging less than a glass of beer or wine a day).

Chen, who is also an instructor in medicine at Harvard Medical School, said that although the women's overall risk of breast cancer was low, they developed the disease at a higher rate than women who were non-drinkers. The elevated risk was most pronounced in those whose tumor growth was stimulated by the hormones estrogen or progesterone. The results were consistent regardless of the women's body mass index, type of alcoholic beverage consumed, or use of hormone replacement therapy.