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Goodbye Hormone Replacement Therapy?

Investigators Now Recommend Many Women Stop Use of Once-Valued Drugs

More than 16,000 women participating in a major clinical trial will be ordered to stop taking hormone medication this week after tests revealed that the 6 million other American women taking the drugs may be at risk.
 

To the surprise and disappointment of researchers and women all over the world, new data shows that the hormones may actually cause more harm than good. Five years into the trial the results have found that taking the combination therapy increased a woman's risk of invasive breast cancer by 26 percent, strokes by 41 percent, and blood clots by 100 percent. In addition, the researchers were stunned to find the therapy did not decrease the risk of coronary heart disease, as was anticipated.

In fact, women in the treatment group saw their risk of heart attack increased by 29 percent. "We now know that the overall risks clearly outweigh the benefits," says Marcia Stefanick, PhD, chair of the study's steering committee and associate professor of medicine at Stanford University. The 16,608 women participating in the trials will be sent letters this week telling them to stop taking the treatment. Results of the trial, called the Women's Health Initiative, or WHI, will be published in the July 17, 2002, issue of The Journal of the American Medical Association, but have been released early due to the significance of the results and the scope of patients affected. Lead investigators recommend that "clinicians stop prescribing this combination for long-term use," and it is expected that these new findings will cause a dramatic change in the treatment of menopause, having significant consequences for all women. "The study results will have a tremendous effect ... they overturn something we've been preaching as 'preventive' for all these years," says Dr. Michael Fleming, speaker of the congress for the American Academy of Family Physicians. "All women need to be re-evaluated and counseled."

Women’s Health Initiative

The WHI trial was designed to identify the potential risks and benefits of treatments that might help prevent heart disease, bone fractures, and breast and colon cancer in postmenopausal women. The estrogen plus progestin arm of the study, originally planned to run for eight and a half years until 2005, followed healthy postmenopausal American women aged 50-79 years for approximately five years. All participants had an intact uterus. Women in the treatment group received a commonly prescribed combination of estrogen and progesterone, which is sold in the U.S. under the trade name Prempro, while women in the non-treatment group received placebos, or "sugar pills." Despite the proclivity for conditions such as breast cancer there was, however, no overall difference in the rate of death between the two groups, and the combination therapy did provide a 37 percent reduced risk of colorectal cancer and a 24 percent reduced risk of bone fractures. Single vs. Combination Therapy for the millions of women now taking hormone replacement therapies, an important distinction of these findings is that they report only on the combination of estrogen and progestin treatment in women who still have their uteruses, and do not indicate that all hormone medications lead to cancer, stroke, and heart disease.

Hormone therapy for menopausal women who have had their uteruses removed by hysterectomy are usually treated with a single hormone treatment of estrogen alone. "Estrogen alone increases the risk of endometrial [a.k.a. uterine] cancer by 8- to 10-fold, but taking progestin greatly decreases this negative effect. So women who have still have their uteruses have to take progestin with estrogen." says Andrea Lacroix, PhD, co-principal investigator of the WHI Clinical Coordinating Center at Fred Hutchinson Cancer Center. Progestin is a very different hormone from estrogen, and has varying effects on the diverse tissues of the body. "For example, progestin acts synergistically with estrogen to stimulate breast tissue, yet protects the uterus by preventing build-up of the lining of the uterine walls," explains Stefanick, who estimates that approximately two-thirds of all post-menopausal women in the U.S. still have their uterus. For the remaining third of postmenopausal women, a separate division of the WHI trial studying estrogen-only therapy in over 10,000 women without a uterus is underway, and results could show the hormone to be of greater benefit and lesser risk for this group. "We do not have information yet on estrogen alone for women without a uterus, but we do know that at this time there is no increase in breast cancer," says Sylvia Smoller, PhD, principal investigator of the WHI New York Clinical Center, and head of epidemiology and biostatistics, Albert Einstein College of Medicine, N.Y. The findings of the WHI so far suggest that it is the combination of estrogen and progestin that poses a danger to women, possibly because of the hormones' effect on the growth cycle of breast cells, though further research is needed to clarify the roles each hormone plays in health and disease. Researchers also note that other combinations, doses, or types of hormones may have different results, though experts anticipate that other combinations of estrogen plus progestin in the pill form will also increase disease rates.

Weighing the Risks

While the increased rates of disease risk seem quite large, the authors note that an overall risk to a large population of women is quite different than the individual risk to a single person. When underscoring the importance of this study, Dr. Wulf Utian, executive director of The North American Menopause Society, cautions that if "incorrectly reported, it could cause panic among hundreds of thousands of women." To help clarify a woman's real risk, Stefanick and other WHI investigators explain that for every 10,000 women taking estrogen plus progestin during one year "eight more will have invasive breast cancer, seven more will have a heart attack, eight more will have a stroke, and 18 more will have blood clots" than will a similar group of 10,000 women not taking these hormones." "However," they are quick to add, "even small individual risks over time, and on a population-wide basis, add up to tens of thousands of these serious adverse health events." So, how should a woman facing menopause make this crucial treatment decision? "Women with a uterus who are currently taking estrogen plus progestin should have a serious talk with their doctor to see if they should continue it," advises Dr. Jacques Rossouw, acting director of the WHI, in a National Institutes of Health press release. And for menopausal women not yet taking estrogen plus progestin, the authors recommend that patients and their doctors concentrate on other proven treatments for preventing heart disease and osteoporosis, and for treating symptoms of menopause including hot flashes, night sweats, vaginal dryness, depression, and sleep disturbances. Years of Unsafe Medicine? "How did it come to be that one of the most commonly prescribed drugs in the country was used for decades in so many millions of women before its long-term effects were ever studied systematically?" said Dr. Jerry Avorn, associate professor of medicine at Harvard Medical School and chief of pharmaco-epidemiology at Brigham & Women's Hospital, Boston. "This is an example of a big gap in U.S. health care and science policy regarding prescription drugs; once a company gets FDA approval for one use (in this case, treatment of the immediate symptoms of menopause, e.g., hot flashes), use can metastasize out of control for any number of other indications for which efficacy and safety have not been demonstrated," says Avron. Other experts point to the fact that hormone replacement therapy was approved by the FDA at a time when standards of safety were less stringent. "The rigors of FDA testing are much different today than when HRT first came into use 60 years ago," says Dr. Susan Hendrix, associate professor of obstetrics and gynecology and principal investigator of the WHI at Wayne State University. While new drugs seeking approval must themselves bear the financial burden of proving patient safety, the government must pick up the bill for funding large-scale studies of drugs which have already been approved. "There seems to be ample marketing dollars to encourage use of such drugs, but it took years to raise the research dollars needed to find out if they actually work and are safe," adds Avron. And though it may be hard for the government to grant the resources necessary for conducting exhaustive safety studies, Lacroix points out that the investment is well worth it. "Large clinical studies are difficult to do and are very expensive, but the WHI results show how greatly these trials are needed."