Q. What is the purpose of the WHI study on combination hormone therapy?
A. The long-term studies in the WHI were initiated because over
the years a number of research studies presented a complicated picture of
the risks and benefits of hormone therapy, and its continued use for
prevention of cardiovascular diseases was controversial. This situation led
the NIH to conduct a large clinical trial of the risks and benefits of
hormone therapy. The WHI set out to examine the long-term effect of estrogen
plus progestin on the prevention of heart disease and hip fractures, while
monitoring for possible increases in risk for breast and colon cancer. The
estrogen plus progestin regimen was given to women who have a uterus since
progestin is known to protect against endometrial cancer, a known effect of
unopposed estrogen. A separate study of estrogen alone in women who had a
hysterectomy was also begun.
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Q. Why were the women in the WHI estrogen plus progestin study told to
stop study pills at this time?
A. In its most recent review of the study data, the WHI Data and
Safety Monitoring Board saw an increased risk of breast cancer in women
taking estrogen plus progestin. The Board also saw that the previously
identified risks for heart attacks, strokes and blood clots to the lungs and
legs had persisted. Therefore, in the judgment of the Board, the overall
risks outweighed the benefits of taking estrogen plus progestin.
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Q. What were the main findings in the WHI study on estrogen plus
progestin?
A. The main findings show that compared to women taking placebo
pills:
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Q. What were the actual hormones that women in the estrogen plus
progestin study were taking?
A. Women who were randomized to receive active hormones were
taking conjugated equine estrogens 0.625 mg each day and medroxyprogesterone
acetate 2.5 mg each day.
This is the most commonly prescribed postmenopausal hormone therapy in
the United States for women who have a uterus (used each day by more than
six million women).
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Q. When did the increased risk of breast cancer become apparent for
women taking estrogen plus progestin compared to women taking placebo pills?
A. There was no difference in the development of breast cancer
during the first 4 years between women taking estrogen plus progestin and
those taking placebo pills. After that time, the numbers began to increase.
After an average of 5.2 years, there was an increased risk of breast cancer
in women taking estrogen plus progestin compared to those taking placebo
pills.
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Q. Is there an increased risk of breast cancer in women taking estrogen
alone?
A. There is no evidence of an increased risk for breast cancer in
women taking active estrogen alone, compared to those taking placebo pills,
even after an average of 5.2 years. We do not know whether the long-term
effects will differ. The Data Safety and Monitoring Board will continue to
review participants' health data every 6 months.
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Q. Is there an increased risk for ovarian cancer with long-term use of
estrogen alone?
A. An observational study of women who took estrogen alone found
that women who used estrogen alone for 10-19 years were twice as likely to
develop ovarian cancer as those who did not use postmenopausal hormones.
(Absolute number was about 7 cases per 10,000 women years compared to 4.4
per 10,000 women years if estrogens were never used.) If women used estrogen
for twenty years or longer, the number increased to 14 per 10,000 person
years.
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Q. How does this new information affect women in the WHI study of
estrogen alone?
A. The Data and Safety Monitoring Board of the WHI will be
reviewing the information about the risks for ovarian cancer and provide
their input to the NIH. The NIH will also send letters to the study
investigators updating them with information which they can discuss with
study participants.
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Q. Do you have recommendations about other hormone alternatives
(lower-dose estrogens, micronized progesterone, natural hormones)?
A. We cannot make specific recommendations about other hormone
medications, such as different estrogens or progestins. We also cannot make
recommendations about hormones women take in lower dosages or in different
ways, such as patches instead of pills.
Futher, without scientific clinical trial data, one cannot assume that
alternative estrogen plus progestin treatments are any safer than those
studied in WHI.
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Q. I am taking prescription hormones, what should I do?
A. We recommend that you talk with your health care provider about
your individual health risk profile and the hormones you are currently
taking.
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Q. Does this new information apply to Selective Estrogen Receptor
Modulators (SERMS) or phytoestrogens?
A. These preparations were not studied in the WHI Hormone Program,
and therefore, we cannot make any conclusions about the risks or benefits of
SERMs, such as raloxifene (Evista®) or tamoxifen (Nolvadex®)
or phytoestrogens.
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Q. How does all of this new information affect my decision to use HRT
for relief from hot flashes, sleep problems and mood swings?
A. The WHI and the observational studies on the risk of ovarian
cancer were long-term studies which were not meant to address the
shorter-term use of HRT. Thus, the information from these studies should be
used by women considering use of HRT for longer than 3 or 4 years.
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