5 Experts Answer: Is Hormone Replacement Therapy Safe?

Each week, MyHealthNewsDaily asks the experts to answer questions about your health.

This week, we asked gynecologists, endocrinologists and oncologists: Is hormone replacement therapy safe? Here's what they said.

Dr. K. Flood-Shaffer, associate professor in the department of obstetrics and gynecology at the University of Cincinnati in Ohio:

"Unfortunately, there is no simple yes or no answer to that question. But the good news is that there is definitely a place a safe place for hormones. The Women's Health Initiative Study (WHI), which began to provide good data in 2004, was the first study to slow the unfettered use of hormones in the United States. The data is still being gathered and that is why there is so much confusion on the matter.

"The current best recommendations are as follows: Not every woman requires (nor should every woman take) hormones. Many women benefit greatly from the judicious use of hormones. For the average woman in the perimenopausal or menopausal period, the reason to start a hormone regimen is very specific. Hormones are to ease the symptoms of hot flushes (flashes), to control irregular bleeding or to treat vaginal dryness. There may be, in some women, an improvement in her overall sense of well being, improvement in sleep patterns or quality of sleep, or improvement in libido -- but none of these are indications to start hormone therapy. Based on the data gathered in the WHI, we know that a woman's risk of heart attack, stroke and development of breast cancer is increased , particularly after more than five years of hormone use (although the greatest risk of heart attack is in the first year of use). We also know, from the WHI, that the risk of osteoporosis and the risk of colon cancer are reduced in women who use hormones. More recent studies have shown that in women who have had a hysterectomy, and therefore use estrogen alone, overall cardiac, bowel, bone and gynecologic health are improved in comparison to women who have not had a hysterectomy and require progesterone in addition to the estrogen.

"That being said, hormones are also NOT a 'forever' medication. Women who have a clear cut indication for hormones and no contraindications (of which there are many), the careful, judicious and temporary use of hormones is considered safe. Women must see their gynecologist, family physician or internist to discuss their own personal situation and risk factors and have a very individualized plan devised for them under close supervision with their physician."


Dr. Joseph Ragaz, medical oncologist and clinical professor of medicine in the School of Population & Public Health at the University of British Columbia in Canada:

"Estrogen alone for breast cancer is highly protective, and if it is taken for women less than age 60 and that's the age when hormone replacement therapy with estrogen should begin it's very safe. It actually reduces heart attacks and does not increase any stroke or clotting. So overall, estrogen-only hormone replacement therapy is very protective from breast cancer. It is safe more safe than originally reported, and much more safe than people perceive. And, paradoxically, it protects against breast cancer rather than enhances the risk. That's a very big shift in thinking, based on the data which we reviewed from the Women's Health Initiative (WHI) hormone replacement randomized, placebo-controlled study.

"Now for hormone replacement therapy that includes progestin Provera, that's much more problematic because for this particular agent, it doesn't have the same safety profile as estrogen alone. But there are other progesterones that are new generation, that have a lower risk of increasing breast cancer rates. They are being tested, but it's not yet fully known about their safety."


Dr. Neil Goodman, chairman of the Reproductive Medicine Committee of the American Association of Clinical Endocrinologists and professor of medicine at the University of Miami in Florida:

"It has to be an individual decision based on a medical evaluation of risk, and there are several times where women should feel that it's safe. That includes women who are obviously healthy and are newly menopausal, who are anywhere from late 40s to early 50s. The lesson from the Women's Health Initiative (WHI) is if you haven't had a period for more than 10 years, there are risks involved [with starting hormone replacement therapy] that are very hard to evaluate. Based on that, the group probably should avoid any hormone therapy unless there's a specific reason to introduce it. And second, we want to use the lowest effective dose.

"The first thing women think about is the breast cancer risk. What we know is that again, back to the young woman in early menopause, the data say that for 10 years [after her last period], she is without an increased risk of either heart disease or breast cancer from the time her menopause starts for the next 10 years. Five is even safer. But if you look at the data, they say 10-year use of the estrogen-progestin hormone therapy do not present a significant risk to this healthy group of women.

"The latest statistics from the WHI in the group of women who had a hysterectomy and were followed on estrogen alone found that after 10 years of follow-up, there was almost a 30 percent reduction in breast cancer in the estrogen-using group, compared to the women who were not using estrogen. I'm not advocating that taking estrogen will reduce a woman's risk of breast cancer, but clearly we don't have any evidence that a young woman in that 40 to 50 age group will have an increased risk of heart disease or breast cancer. This information shouldn't be applied to every woman, but for healthy women it's very safe to take estrogen AND progesterone, which is needed if you have a uterus, to avoid the other risk, which is endometrial cancer.

"The big controversy is women taking daily progesterone after 10 years may be at a higher risk of breast cancer. So what people have advocated now is women should be either on cyclic meaning not every day or less frequent progesterone exposure to avoid what might be an increased risk of breast cancer, but only after 10 years. The point here is it's important to realize that this is safe for women to treat their symptoms."


Dr. Michael A. Thomas, professor and director of the Division of Reproductive Endocrinology and Infertility at the University of Cincinnati in Ohio:

"In my opinion, hormone replacement therapy [HRT] is a safe alternative for patients in the perimenopause or menopause. After the results of the Women's Health Initiative, the number of patients using HRT decreased significantly. Though the patients with an intact uterus using HRT with estrogen and a continuous progestin showed an increase in breast, clotting and cardiovascular problems, there was no increase in breast problems with the estrogen-only group without a uterus.

"More recent data shows that estrogen-only patients in the WHI showed a decrease in breast cancer compared to placebo takers. From this, you can assume that if you do not take estrogen in the patients without a uterus and if you space out the use of progestins to 10 to 12 days each month or 12 days every other month, you may indeed negate any risk of breast problems. Keep in mind that more women get breast cancer off hormones than on.

"Also, you get your best results from HRT if you start it within one to two years after menopause. There is no reason to start it if you are five years from menopause."


Dr. John E. Buster, professor of obstetrics and gynecology at Warren Alpert Medical School at Brown University, and associate director of the Division of Reproductive Endocrinology at the Women & Infant's Hospital of Rhode Island:

"Up to 75 percent of the 37 million women in the United States at or near menopause experience symptoms of estrogen withdrawal, primarily hot flashes. Hot flashes are a significant quality of life issue because many of these women experience associated debilitating symptoms: depression, mood swings, insomnia, fatigue, dysfunctional family and workplace relationships, low professional productivity and loss of self esteem. Estrogen treatment, done as replacement of the deficient hormone, is the most effective therapy available for hot flashes.

"Reports from nearly 10 years ago publicized concern of oral estrogens, administered with a progestin, as being associated with a small increased risk of breast cancer. A most recent update of that study, however, reports that when the estrogen moiety is administered without the progestin, the risk of breast cancer is significantly lower (not higher) than the controls when followed over 15 years after exposure. Most recent regimens exploit low-dose delivery of natural estradiol (the depleted hormone) through the microcirculation of the skin given as patches, gels or sprays. I've collaborated in the development of one of these, called Evamist.

"Because these regimens are not oral, they bypass the liver avoiding the problem of clearing a large dose of steroid through the liver where it modifies proteins that include clotting factors, lipoproteins and inflammatory factors. These liver protein aberrations have been associated with many of the adverse effects of therapeutic estrogens. Because there is evidence that newer transdermal estrogens significantly enhance safety of menopausal hormone replacement, some physicians may prefer transdermal regimens to oral regimens in clinical practice."

Pass it on: Hormone replacement therapy is safe to relieve menopausal symptoms if taken right at the start of menopause, and estrogen-only hormone replacement therapy has actually been shown to reduce breast cancer risk. However, women should consult their doctor about their individual risks before starting hormone replacement therapy.

Follow MyHealthNewsDaily staff writer Amanda Chan on Twitter @AmandaLChan.

Amanda Chan
Amanda Chan was a staff writer for Live Science Health. She holds a bachelor's degree in journalism and mass communication from the Walter Cronkite School of Journalism and Mass Communication at Arizona State University, and a master's degree in journalism from Columbia University.