How does menopausal hormone use affect the risk of ovarian cancer?

Several observational studies have found that the use of estrogen alone is associated with a modest increased risk of developing ovarian cancer. One study that followed 44,241 menopausal women for approximately 20 years concluded that women who used estrogen alone for 10 or more years were twice as likely to develop ovarian cancer compared with women who did not use menopausal hormones (16). Another recent, large, observational study also found an association between estrogen use and death due to ovarian cancer. In this study, the increased risk appeared to be limited to women who used estrogens for 10 or more years (17). 

The most direct evidence about the risk of ovarian cancer in women who use estrogen plus progestin comes from the randomized WHI study (10). These data suggest that there may be an increased ovarian cancer risk with combined hormone use. After 5.6 years of followup, a 58-percent increased risk of ovarian cancer was reported in the women using estrogen plus progestin compared to the nonusers, but the increased risk was not statistically significant. One observational study suggested that combined estrogen-progestin regimens do not increase the risk of ovarian cancer if progestin is used for more than 15 days per month (18), but this study was too small to draw firm conclusions. More research is needed to clarify the relationship between menopausal hormone use, particularly for combined therapy, and the risk of ovarian cancer.

Questions and Answers About Menopausal Hormone Use

• What is menopause?

• What are menopausal hormones and why are they used?

• How do scientists determine the health outcomes associated with hormone use?

• Do the benefits of hormone use after menopause outweigh the risks?

• What are the effects of hormone use on the uterus?

• How does menopausal hormone use affect breast cancer risk and survival?

• How does menopausal hormone use affect the risk of ovarian cancer?

• What are the effects of menopausal hormones on heart disease?

• What are the effects of menopausal hormones on bone health?

• What are the effects of postmenopausal hormone use on quality of life and cognitive functions, specifically memory and learning?

• Are there other benefits or risks associated with menopausal hormone use?

• What are the risks of menopausal hormones for women who have a history of cancer?

• Does the route of administration of hormones make a difference?

• Are there any alternatives for women who choose not to take menopausal hormones?

• What research still needs to be done?