This article by The Women’s Health Initiative describes a large hormone replacement therapy study that was discontinued due to health risks for the women who were taking the hormones. The researchers halted the study prematurely because participants on hormone replacement therapy exceeded the boundary for breast cancer risk that was established at the beginning of the study. There was also an increased risk for heart disease for participants on hormone replacement therapy compared to the placebo group.
Hormone Replacement Therapy in the News:
The Women’s Health Initiative Study at a Glance
Hormone replacement therapy (HRT) has been in the news for the past few months due to the release of findings from the Women’s Health Initiative (WHI) in the United States. Here’s an update and short summary of the main findings of this research:
When did the study take place?
The study began in the fall of 1997 and was scheduled to be completed in 2005. However, researchers halted the study midway on May 31, 2002 because they felt that the health risks for participants taking hormone replacement therapy outweighed the possible benefits of hormone replacement therapy.
Who took part in the study?
More than 16,000 healthy post-menopausal American women with a uterus between the ages of 50 and 79.
What form of Hormone replacement therapy was evaluated?
Participants were given a placebo or .625 mg of conjugated equine estrogen and 2.5 mg of medroxyprogesterone acetate (hormone replacement therapy, estrogen plus progestin) in 1 tablet daily for an average of 5.2 years. The study was designed to evaluate the use of hormone replacement therapy by healthy women for disease prevention.
Why was the study halted?
The researchers halted the study prematurely because participants on hormone replacement therapy exceeded the boundary for breast cancer risk that was established at the beginning of the study. There was also an increased risk for heart disease for participants on hormone replacement therapy compared to the placebo group.
What are the relevant findings from this study?
The study suggests that long-term (more than 4 years) use of hormone replacement therapy increases a woman’s risk for heart disease and breast cancer. The study demonstrated no significant increased risk of breast cancer for women taking hormone replacement therapy for less than 4 years.
Who needs to be concerned?
Researchers suggest that women who have been on combined hormone replacement therapy (estrogen plus a progestin) for more than 4 years should consult their doctors about whether they need to continue on hormone replacement therapy, and address their increased risks for breast cancer and heart disease for continued use of Hormone replacement therapy.
Researchers also suggest that women taking hormone replacement therapy solely for heart disease prevention should stop taking hormone replacement therapy and consider other options.
While the study found that hormone replacement therapy does reduce the risk for fractures, researchers nevertheless suggest that women taking hormone replacement therapy to prevent osteoporosis should weigh the risks of hormone replacement therapy against the possible benefits with their doctors, and consider other, non-hormonal options for the treatment of osteoporosis.
What happens next?
The Women’s Health Initiative study of unopposed estrogen (estrogen alone) therapy for women without a uterus will continue as planned since there is currently no sign of an increased risk of breast cancer for participants. Study results will be released after the trial end in March 2005.
Sources: http://www.nhlbi.nih.gov/new/press/02-07-09.htm ; JAMA 288(3), 321-333; A Friend Indeed May-June 2002; www.afriendindeed.ca
Written by Kathleen O’Grady, Director of Communications for the Canadian Women’s Health Network and Editor of A Friend Indeed newsletter. Reprinted with permission from A Friend Indeed (Sep/Oct 2002).
WHI, Estrogen and Progestin trial, update (March 2004)
The National Institutes of Health (NIH) has instructed participants in the estrogen-alone study of the Women’s Health Initiative (WHI), a large multi-center trial, to stop taking their study pills and to begin the follow-up phase of the study.
Researchers concluded that, with nearly 7 years of follow-up completed, estrogen-alone hormone therapy does not appear to affect (either decrease or increase) the risk of heart disease–the main question of the trial. More importantly, there appears to be an increased risk of stroke, and the NIH believes that an increased risk of stroke is not acceptable in a prevention trial in healthy women, especially if estrogen does not reduce heart disease risk.
Why did the NIH stop the trial? Your questions answered: http://www.nhlbi.nih.gov/whi/e-a_faq.htm
More on Menopause and Hormone Replacement Therapy from the Canadian Women’s Health Network!
Full article: http://www.cwhn.ca/resources/menopause/Hormone replacement therapy-glance.html