Tuesday, researchers reported a new wrinkle: Those estrogen-only users doubled their chances of getting non-cancerous breast lumps. That's a concern not only because of the extra biopsies and worry those lumps cause, but because a particular type - called benign proliferative breast disease - is suspected of being a first step toward developing cancer 10 years or so later.
About one in five women undergo a breast biopsy within a decade of starting annual mammograms, and most of those abnormalities turn out to be benign. Yet under a microscope there are different types, from simple fluid-filled cysts to what's called proliferative breast disease, because it's made of growing cells.
The latest work, published in the Journal of the National Cancer Institute, re-examines data from the landmark Women's Health Initiative that found a variety of health risks from long-term hormone therapy.
Only women who have undergone hysterectomies are able to use estrogen-only therapy, and the WHI originally included more than 10,000 of those women who were given either estrogen or a dummy drug and tracked for about seven years.
Now, a team led by Dr. Tom Rohan of the Albert Einstein College of Medicine in New York has reviewed breast biopsies done on those women - and identified 232 cases of benign proliferative breast disease. Women given the estrogen-only therapy had twice the risk of developing these abnormalities compared with women given a placebo.
WHI participants are still being tracked, allowing scientists to eventually tell if the benign breast problems were a signal of more trouble to come, Rohan concluded.
http://accesswdun.com/article/2008/4/208845