Hormone Therapy Linked to Risk of Ovarian Cancer
Tue Apr 2, 5:39 PM ET  2002

NEW YORK (Reuters Health) - Certain types of hormone replacement therapy
may increase the risk of ovarian cancer in women who take the drugs
after menopause, according to a study released on Tuesday. Those taking
the drugs for more than 10 years seem to be at the greatest risk for
ovarian cancer.

However, the increase in risk is relatively modest and should be weighed
against the potential health benefits of hormone replacement, according
to Dr. Tomas Riman, from Falu Hospital, Sweden, and colleagues. Past
studies have shown that hormone replacement therapy can reduce the risk
of bone-thinning, and possibly heart disease though that has not yet
been proven.

"We advocate cautious interpretation of our results and do notrecommend
changes to  current hormone replacement therapy prescribing practices,"
Riman and colleagues report in the April 3rd issue of the Journal of the
National Cancer Institute (news - web sites).

"For women to make an informed decision on whether or not to use hormone
replacement therapy, all beneficial and adverse hormonal aspects
concerning osteoporosis, coronary heart disease, venous thrombosis
(blood clot formation) and other health effects must be addressed," they

In the study, the researchers compared 655 women with ovarian cancer to
nearly 4,000 healthy women the same age. All the women were 50 to 74
years of age.

Compared with women who had never used estrogen replacement therapy,
women who took estrogen alone were at increased risk of ovarian cancer.

Women who used estrogen with sequentially added progestins--a cyclic
regimen of the second hormone--were also at an increased risk of ovarian
cancer compared with women who had never used estrogen.

However, women who used hormone replacement therapy with continuously
(daily) added progestins were no more likely to develop ovarian cancer
than those who never had used hormones. Taking estrogen alone is know to
increase the risk of cancer of the uterine lining, so most women now
also take progestin, a synthetic form of the hormone progesterone, as
part of hormone replacement therapy.

The greatest increased risk of ovarian cancer was seen among women who
had used estrogen with sequentially added progestins for more than 10

However, the researchers note that the possible increase in risk is
still relatively modest. Of 1,000 women taking estrogen alone or in
combination with sequential progestin, 2 to 3 might develop ovarian
cancer as a result of the treatment.

 SOURCE: Journal of the National Cancer Institute 2002;94:497-504.