The Family Health Guide

ERT and the Risk of Ovarian Cancer

Ovaries and Fallopian Tubes

Return to Chapter Index

ERT and the Risk of Ovarian Cancer

Another strike against hormone replacement therapy has emerged. The results of a study published in the July 17, 2002, issue of the Journal of the American Medical Association show women who take estrogen replacement therapy, particularly for an extended period, have an increased risk for ovarian cancer.

The study involved over 44,000 women enrolled in a nationwide breast cancer-screening program between 1979 and 1998. Follow-up interviews and questionnaires revealed 329 women in the study developed ovarian cancer over the 20-year period. Use of estrogen-only replacement therapy for any length of time was associated with an increased risk of ovarian cancer. The researchers found the results were consistent regardless of other risk factors for ovarian cancer, such as age, type of menopause (surgical or natural), and use of oral contraceptives. The risk of cancer also appeared to increase with the length of estrogen use; women who took estrogen for over 20 years had 3 times the risk of developing ovarian cancer. The results were similar in women who had a hysterectomy; such women are more likely to take estrogen for prolonged periods of time.

Women who have not had a hysterectomy are usually prescribed an estrogen-progestin combination to protect against endometrial cancer. Results of the study showed women taking short-term combined hormone therapy did not have an increased risk for ovarian cancer. However, women who took combined therapy after having taken estrogen-only therapy were still at an increased risk. The practice of taking combined hormone therapy is relatively recent; therefore, further time and study may be needed to accurately evaluate the risk of ovarian cancer associated with its use.

Combination therapy was the subject of controversy surrounding the Women's Health Initiative, which found that such therapy increased risk for breast cancer, blood clots, and stroke. However, the estrogen-only arm of the study is still ongoing, having found no significant adverse effects.

The risk of ovarian cancer should not be considered lightly — this form of cancer causes more deaths than any other genital cancer. Ovarian cancer is also notoriously difficult to diagnose at an early stage. These factors, combined with the results of the study, add one more issue for women to consider when deciding whether to take or continue estrogen replacement therapy.

September 2002 Update

Back to Top