Study upholds breast cancer mortality for hormone replacement
In the nearly 11 years since researchers first rang alarm bells that women on hormone replacement therapy had an increased risk of breast cancer, some have suggested that taking estrogen and progestin to treat symptoms of menopause might not be so dangerous after all.
Though it was generally agreed that women who took the two hormones to curb their hot flashes and night sweats upped their chances of developing the disease, many studies suggested that the cancers the women developed were less likely to be deadly.
A new analysis of data from the Women's Health Initiative casts doubt on those findings. The study, published by the Journal of the National Cancer Institute, concludes that the prognosis for cancers related to hormone replacement therapy is just as dire as for other breast cancers. As a result, women who turn to the treatment are more likely to die of breast cancer than their non-hormone-taking peers.
“You could fill a basketball arena with the women who get the disease,” said Dr. Rowan Chlebowski, the principal investigator for the Women's Health Initiative and lead author of the study. “It seems like you'd want to reach a higher threshold before you take it.”
Nearly 70,000 postmenopausal women participated in randomized clinical trials as part of the Women's Health Initiative project. The study participants who took estrogen plus progestin had higher rates of breast cancer diagnoses and of breast cancer deaths.
At the same time, more than 90,000 additional women took part in a related observational study that tracked details about their health and hormone use over an average of 11 years. Along with many other observational studies, this one found that women who took hormones to treat menopause symptoms and got breast cancer were less likely to die from the illness than women who got breast cancer without taking hormones.
The new findings apply only to women who take estrogen and progestin, a synthesized form of the natural hormone progesterone. Women who have had hysterectomies can take estrogen alone, a regimen that doesn't seem to increase breast cancer risk. But those who still have a uterus must take both estrogen and progestin to avoid developing endometrial cancer.
Dr. Joanne Mortimer, director of the Women's Cancers Program at City of Hope Cancer Center in Duarte, Calif., said that in general, she does not recommend hormone replacement therapy for patients with menopause symptoms.