Questions:
Questions and Answers About the WHI Postmenopausal
Hormone Therapy Trials
Questions and Answers About Estrogen-Plus-Progestin
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 did not appear
to affect (either decrease or increase) the risk of heart
disease, the main question of the trial. More importantly,
there appeared 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 felt that, with nearly 7 of the expected
8 years of follow-up completed, the study results were 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.
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Q. What are the study's findings?
A. The following findings show disease risks of
estrogen-alone use compared to placebo. The number of
cases given represent an average for every 10,000 women
each year:
-
Fatal and non-fatal strokes. Increased risk--12 cases
more (44 cases in those on estrogen alone and 32 in
those on placebo).
-
Venous thrombosis (blood clot, usually in one of the
deep veins of the legs). Increased risk--6 cases more
(21 cases in those on estrogen alone and 15 in those on
placebo).
-
Coronary heart disease. No significant difference in
risk (neither increased nor decreased)--5 fewer cases
(49 cases in those on estrogen alone and 54 in those on
placebo).
-
Colorectal or total cancer. No significant differences
in risk (neither increased nor decreased)--1 more case
for colorectal cancer and 7 fewer cases for total cancer
(for colorectal cancer, 17 cases in those on estrogen
alone and 16 in those on placebo; for total cancer, 103
cases in those on estrogen alone and 110 in those on
placebo).
-
All deaths or those for a specific cause. No significant
difference in risk (neither increased nor decreased)--3
more deaths (for all deaths, 81 in those on estrogen
alone and 78 in those on placebo).
-
Breast cancer. Uncertain effect--7 fewer cases (26 cases
in those on estrogen alone and 33 in those on placebo).
This finding was not significant.
-
Bone fractures. Increased benefit--6 fewer hip fractures
(11 cases in those on estrogen alone and 17 cases in
those on placebo).
The results did not differ by race or ethnicity, or body
mass index (BMI).
A separate report will be published in the near future
about the effect of estrogen alone on dementia and
cognitive function. That 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. In 2003, WHIMS reported an increased risk
of dementia in women taking estrogen plus progestin who
were aged 65 and older.
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Q. What happens now with the estrogen-alone study?
A. Participants were asked on March 1, 2004, to stop their
study medication and are being told whether they took the
active drug or the placebo. WHI also gave this information
to the women's personal health care provider, if desired.
Participants were asked to continue in the follow-up phase
of the study, which is due to last until 2007. During the
follow-up phase, the women will continue to undergo tests
to monitor their health, including annual mammograms.
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Q. What happens with the WHI--is it ended?
A. The WHI was launched in 1991 and consists of a set of
clinical trials and an observational study, which together
involve more than 161,000 generally healthy postmenopausal
women.
The clinical trials were designed to test the effects of
postmenopausal hormone therapy, diet modification, and
calcium and vitamin D supplements on heart disease,
fractures, and breast and colorectal cancer.
-
The hormone trial had two studies--of estrogen-alone
therapy and of estrogen-plus-progestin therapy. Those
studies have now ended. The women in these studies are
now participating in a follow-up phase, which should
last until 2007.
-
The clinical trials on diet modification, and calcium
and vitamin D supplements are continuing as planned and
should end in 2005. The participants will then enter a
follow-up phase.
The
observational study is looking for predictors and
biological markers for disease. It is continuing as
planned and should end in 2005.
Analyses of data from the WHI studies are under way and
further findings will be reported.
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April 2004 |
