Physicians have long known that taking estrogen alone will increase the risk of uterine (endometrial) cancer, and that the addition of progestin — the other major female hormone — will greatly reduce the risk.
So for many years, most women — except those whose uteruses have been removed — who take estrogen also have been taking progestin. For a while, there was hope that the progestin would not only reduce the risk of uterine cancer but the risk of breast cancer.
But several studies in recent years have led most researchers to conclude that the combination of estrogen and progestin carries a higher risk of breast cancer than does taking estrogen alone.
In this week’s Journal of the American Medical Association, another such study appeared, leading three top cancer-risk experts to write in an editorial that the “addition of progestin to estrogen does not reduce risk of breast cancer and [researchers] suggest that risk is actually increased.”
The amount of increased risk varies with each study but may be as high as 80 percent after 10 years of combined — estrogen plus progestin — hormone therapy. The experts also hasten to add that this increased risk has not been finally proven with randomized studies, but the evidence so far is very suggestive.
What Should Patients
So what are the millions of women taking estrogen plus progestin to do?
First, I would stress that no one should suddenly stop taking these hormones; this is not a medical emergency.
Second, the data clearly indicate that women who took these hormones for just a few years and are no longer taking them are at no added risk. And that means that women who want to take them for a few years at the beginning of menopause to treat symptoms should not worry about such short-term use.
But what about those of you who have taken, or plan to take, them for long periods because you have a significant risk for osteoporosis or heart disease? Even for you, there may be some good alternatives, including:
Consider significant lifestyle changes in diet and exercise. Both can greatly reduce the risk for both heart disease and bone thinning. And stopping smoking would be far more helpful than taking hormones.
Consider other medications specifically targeted at lowering cholesterol and/or preventing bone loss. That could render estrogen no longer necessary. For example, so-called statin drugs can significantly reduce dangerous cholesterol, and the biophosphates can reduce the risk for bone thinning.
Consider the new “designer estrogens,” such as raloxifene and tamoxifen. They may provide the benefits of estrogen without the risks. (We don’t have final proof of this, but we may within a few years.)
In other words, there may be good alternatives for many women to estrogen-progestin therapy. But all of these decisions should be made only after careful consideration of each individual woman’s complete situation — family history, other risk factors, current symptoms, etc.
For example, a woman with a very strong family history of premature heart disease and a woman with a very strong family history of breast cancer would think very differently about taking hormone replacement therapy.
But quite frankly, many physicians are simply not equipped — either emotionally or informationally — to help you with this important decision, so you may have to go to a specialist in women’s health issues to get the support and advice you need.
Good luck with a tough decision.
Dr. Timothy Johnson is the award-winning medical editor for ABCNEWS. His new column will appear every other Friday on ABCNEWS.com. You also can see his reports on ABCNEWS on-air broadcasts including Good Morning America, 20/20, World News Tonight and Nightline. Johnson holds joint positions in medicine at Harvard University and Massachusetts General Hospital in Boston.