The Journal of the National Cancer Institute carries in its April 8 online issue another report that links conjugated equine estrogen, a form of hormone replacement therapy (HRT), to benign breast disease in women. The current study is based on biopsies taken from 10,739 postmenopausal women who’ve had hysterectomies and were a part of the Women’s Health Initiative study. For the initiative, women were divided into two groups, with one receiving conjugated equine estrogen and the other a placebo.

Tom Rohan, MD, PhD, and his colleagues at the Albert Einstein College of Medicine, New York, examined noncancerous breast biopsies from the women in the initiative. They identified a total of 232 women with benign proliferative breast disease. Of these 232 cases, 155 of them were in women taking the estrogen therapy and only 77 of them in the control group taking the placebo. The numbers indicate a risk greater than two-fold of developing benign breast disease when taking the estrogen therapy.

It is widely believed in the medical community that benign proliferative breast disease is the first step toward developing cancer. There is, at this time, no evidence of increased risk for developing breast cancer in the women taking the estrogen therapy for the initiative but the findings of Rohan’s study suggest the importance of continuing follow-up monitoring of study participants.

Source: Journal of the National Cancer Institute