Estrogen Replacement Therapy May Increase Risk of Ovarian Cancer

Two studies released within the last week, one by the American Cancer Society (ACS) and one by the National Cancer Institute (NCI), report that the prolonged use of estrogen replacement therapy (ERT) to relieve the symptoms of menopause may increase women’s risk of dying from ovarian cancer. The ACS surveyed over 200,000 post-menopausal women from 1982 – 1996 and the NCI study nearly 45,000 post-menopausal women from 1979 – 1986. About 1 in 59 women develop ovarian cancer, and according to the ACS, prolonged estrogen use (10 years or longer) increase a woman’s risk of ovarian by 2.2 times, or a 1 in 27 chance. However, the NCI reported that women who used the hormone for as little as four years increased their risk of ovarian cancer. The ACS also reported that the increased risk of ovarian cancer remains for up to 29 years after stopping ERT. The NCI found that women who used a combination estrogen and progesterone or hormone replacement therapy (HRT) to treat the symptoms of menopause did not appear to be at a greater risk of ovarian cancer than women who had never used HRT or ERT.

Researchers at the ACS and the NCI recommend more studies before eliminating ERT or making any other drastic changes in menopausal hormone treatment, because long term estrogen use has been associated with lower rates of osteoporosis, colon cancer and heart diseaseÑdiseases much more common in women than ovarian cancer. Earlier studies have also show that HRT may increase a woman’s risk of breast cancer. Women are urged to talk with their doctors regarding questions about ERT, HRT, ovarian cancer, and heart disease.


American Cancer Society Ð March 26, 2001; National Cancer Institute Ð March 26, 2001; Washington Post Ð March 20 & 26, 2001

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