Study: Estrogen increases ovarian cancer risk

By Rhonda Rowland
CNN Medical Unit

ATLANTA, Georgia (CNN) -- Women who use supplemental estrogen after menopause for 10 years or more double their risk of dying from ovarian cancer, according to a study released Tuesday. This increased risk persists up to 29 years after a woman stops using the hormone therapy.

But doctors said women who currently use hormone therapy should not be alarmed by these findings.

"The actual risk of dying from ovarian cancer is small. It's 1 percent. In long-term estrogen users, that risk increased to 2 percent," said Dr. Carmen Rodriguez, senior epidemiologist at the American Cancer Society.

The study, published in the Journal of the American Medical Association, is the first to find a link between estrogen use and ovarian cancer deaths. Researchers followed the health status of 211,581 women who reached menopause between 1982 and 1996.

"We also found women who had previously used estrogen had a 23-percent increased risk of dying from ovarian cancer, and current users had a 51-percent increased risk," said Rodriguez, the lead investigator.

Doctors said the study should be viewed in perspective.

"The way we prescribe hormones has changed since this study began in 1982," said Dr. Celia Dominguez, reproductive endocrinologist at Emory University. "Unless a woman has had a hysterectomy, women now take estrogen combined with progesterone. This study did not look at the possible protective role of progesterone."

It's well-known that estrogen alone increases the risk of endometrial cancer in women who still have a uterus. The combined regimen of estrogen and progesterone protects against endometrial cancer.

"Still, the study is significant since we want to look at anything that may increase the risk of cancer," said Dominguez. "If you've taken estrogen for a long period of time, you may want to discuss this with your doctor."

Researchers said more studies are needed to examine the possible link between ovarian cancer and hormone replacement therapy.

"In the meantime, women considering hormone replacement therapy should review all the risks and benefits with their physician," said Rodriguez. She added that women who never had a child, never used oral contraceptives and women with a family history of ovarian cancer "may want to reconsider using hormone therapy."

According to the American Cancer Society, 13,900 women will die this year from ovarian cancer. This type of cancer is very deadly since it's difficult to detect at an early stage when it's most curable. By comparison, 40,200 women will die from breast cancer.

Hormone replacement may influence mammography accuracy
January 9, 2001
Hormone therapy fails to slow heart disease in older women, study finds
March 13, 2000
Breast cancer risk greater with estrogen/progestin combination, study reports
January 25, 2000

American College of Obstetricians and Gynecologists
The Hormone Foundation
National Institutes of Health: Women's Health Initiative
North American Menopause Society

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.