Questions and Answers about estrogen-alone trial decision
- Why did the NIH stop the trial?
- What are the study's findings?
- What are you telling study participants?
- What advice can you give to women about taking estrogen-alone and combination hormone therapy?
Q. Why did the NIH stop the trial?
A. The NIH carefully reviewed the latest data and 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.
Further, the NIH believes that, with nearly 7 of the expected 8 years of follow up completed, the study's results are not likely to change if the trial continued for another year. The NIH believes that enough data are available to give an overall assessment of the risks and benefits of the estrogen use in this trial.
Q. What are the study's findings?
A. Analysis of the data from the study began as soon as the study stopped. However, it will take time to complete the analysis. Publication in a peer-reviewed journal is expected in about 2 months. Until then, it can be said that the estrogen-alone therapy appears to have no effect on heart disease risk. It appears to increase the risk of stroke and decrease the risk of hip fracture. It does not increase the risk of breast cancer during the time period of this trial.
Until the analysis is done, it can only be said that the increased risk of stroke from estrogen alone appears to be similar to that seen in the estrogen-plus-progestin study when it was halted in July 2002. In that study, women taking estrogen plus progestin had 8 more strokes per year for every 10,000 women than those taking the placebo. (For every 10,000 women taking estrogen-plus-progestin therapy, there were 29 strokes a year, compared with 21 for women not on the treatment.) However, there are differences in the two studies' results. The estrogen-plus-progestin study found an increased risk of heart disease and breast cancer. Both studies found a decreased risk of hip fractures.
A separate report will contain information on women age 65 and older who participated in the estrogen-alone WHI Memory Study (WHIMS), an ancillary study of the WHI hormone trials. Preliminary data suggest that, for the WHIMS participants who were on estrogen alone when compared to the women who were taking placebo, there was a trend toward increased risk of probable dementia and/or mild cognitive impairment. In 2003, WHIMS reported an increased risk of dementia in women taking estrogen plus progestin who were aged 65 and older.
Q. What are you telling study participants?
A. Participants in the WHI estrogen-alone study are being given the preliminary findings and instructions on what to do. They have received letters from Dr. Barbara Alving, the Acting Director of the National Heart, Lung, and Blood Institute, and their clinic investigator. Additionally, they can call their clinic. Clinics will hold briefings about the findings, and information will be posted on a special Web site and sent to participants in a newsletter.
Participants are being asked to stop their study medication and will be told whether they took the active drug or the placebo. WHI will give this information to the women's personal health care provider, if desired. Also, the participants are being asked to continue in the follow-up phase of the study.
Q. What advice can you give to women about taking estrogen-alone and combination hormone therapy?
A. Hormone therapy should not be taken to prevent heart disease. We recommend that women follow the FDA's advice on hormone therapy. It states that postmenopausal women who use or are considering using estrogen or estrogen with progestin discuss the therapy's benefits and risks with their physicians. These products are approved therapies for relief from moderate to severe hot flashes and symptoms of vulvar and vaginal atrophy. Although hormone therapy is effective for the prevention of postmenopausal osteoporosis, it should only be considered for women at significant risk of osteoporosis who cannot take non-estrogen medications. The FDA recommends that estrogens and progestins should be used at the lowest doses for the shortest duration needed to achieve treatment goals.
Posted: February 2004
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