Two New Hormone Replacement Therapy Reviews Support Findings of Recently Halted Clinical Trial

Press Release Date: August 20, 2002

Two new systematic reviews of a broad spectrum of research on hormone replacement therapy (HRT) to prevent cardiovascular disease and other long-term health problems support the findings of a recently halted clinical trial in the Women's Health Initiative (WHI). These reviews were developed for the U.S. Preventive Services Task Force as background for new recommendations on HRT use that will be published in the fall for clinicians and patients.

The two reviews, one in the August 20 Annals of Internal Medicine and the other in the August 21 Journal of the American Medical Association (JAMA), found that for women taking HRT for 5 years or longer to prevent chronic conditions, harms could exceed benefits. The reviews were not able to determine whether the harms or benefits depended on type of hormones used. Although one study of estrogen and progestin in the WHI was stopped after 5 years because harms exceeded benefits, a second study of estrogen alone for women who have had a hysterectomy is continuing because the balance of benefits and harms is not yet clear.

The Annals article primarily addresses cardiovascular disease, and the JAMA article is an overall summary of the risks and benefits of HRT. The reviews did not examine the use of HRT to treat menopausal symptoms or specific conditions such as osteoporosis.

The JAMA article confirms the benefits of HRT to prevent bone fractures and probably colorectal cancer but found that the effects of HRT on dementia were uncertain. Harms include an increased risk of blood clots and stroke, an increase in breast cancer with 5 or more years of use, and a probable increase in gallbladder disease. New evidence suggests that HRT does not reduce the risk of heart disease and may modestly increase risk.

The reviews were funded by the Agency for Healthcare Research and Quality (AHRQ), which sponsors the Task Force. Data from the WHI trial were incorporated into the Annals and JAMA articles in an effort to integrate those results with systematic reviews of thousands of studies published on HRT since 1996. The Task Force, an independent panel of experts, will be reviewing these new systematic reviews in the next few months to update its 1996 recommendations on HRT.

HHS is leading the federal government's effort to ensure that clinicians and patients have the latest available scientific evidence on HRT use.

On Oct. 23-24, the National Institutes of Health will host a public meeting that will bring together researchers, health care practitioners, knowledgeable groups and consumers to review the currently available scientific information and ongoing clinical trials regarding HRT. The meeting will provide information about what recent study results mean for women who are taking HRT and what alternatives are available for specific conditions.

Subsequently, the FDA will host a public session to review the extent to which the WHI results might be extrapolated to other combination estrogen/progestin products and doses, the known benefits for approved indications in light of these new data, and the WHI's implications for future clinical trials of hormone therapy.

HRT, in the form of estrogen alone or combined with progestin, is taken by 14 million U.S. women. It is used by women to reduce acute symptoms of menopause such as hot flashes, and physicians have prescribed it to prevent chronic conditions such as heart disease. Heart disease is the leading cause of death among women in the United States.

The Task Force, the leading independent panel of private-sector experts in prevention and primary care, conducts rigorous, impartial assessments of all the scientific evidence for a broad range of preventive services. Its recommendations are considered the gold standard for clinical preventive services. The reviews were conducted by research teams led by Heidi Nelson, M.D., M.P.H., and Linda Humphrey, M.D., M.P.H., at AHRQ's Evidence-based Practice Center at Oregon Health & Science University.

The reviews are available online.

For additional information, please contact AHRQ Public Affairs, (301) 427-1364.

---

Internet Citation:

Two New Hormone Replacement Therapy Reviews Support Findings of Recently Halted Clinical Trial. Press Release, August 20, 2002. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/news/press/pr2002/hrtrevpr.htm

---