Breast cancer risk drops after ending HRT

Postmenopausal women who stopped hormone replacement therapy — estrogen plus progestin — had a decline in breast cancer risk, U.S. researchers found.

A study from the Women’s Health Initiative, led by Dr. Rowan T. Chlebowski of the Los Angeles Biomedical Research Institute, supports the hypothesis that the recent reduction in breast cancer incidence in the United States is predominantly related to a decrease in combined estrogen plus progestin use.

The researchers used data from the Women’s Health Initiative’s randomized trial and observational study cohort of postmenopausal women on combined hormone therapy of estrogen and progestin.

The study, published in The New England Journal of Medicine, found that continued use of combined estrogen plus progestin after five years about doubles subsequent breast cancer risk each year.

Postmenopausal women and their physicians should consider these findings in weighing the risks and benefits of combined estrogen plus progestin use, especially if the women plan to take the medication for more than five years, Chlebowski said in a statement.