Ovarian Cancer - Risk Factors

Risk factors that can be controlled

Delayed childbirth: Having a first child after age 30 or never having children increases the risk for ovarian cancer and breast cancer. Pregnancy seems to decrease the risk of ovarian and breast cancer if a woman becomes pregnant with her first child before age 30. This is because there is an interruption of menstrual cycles during pregnancy. Women who never become pregnant are at a higher risk of ovarian and breast cancer than those who have a first child before age 30. However, pregnancy after age 30 appears to also increase the risk of ovarian and breast cancer. The older a woman is, the more likely her ovarian and breast tissue has already been exposed to some cancer-causing substances called carcinogens. Therefore, exposure to elevated hormone levels during pregnancy at a later age may stimulate the growth of abnormal ovarian or breast tissue. In fact, some experts believe that the number of menstrual cycles that occur between a woman’s first menstrual period and her first pregnancy is a greater predictor of ovarian cancer and breast cancer risk than her age at her first menstruation or menopause.

Use of fertility drugs: Some research has suggested that women who use (or have used) fertility drugs are at higher risk of developing ovarian cancer. In particular, the fertility drug clomiphene citrate may increase the risk of ovarian cancer. The risk may be greater if the woman does not become pregnant from using fertility pills. Women who are considering fertility drugs should talk to their physicians about the benefits and risks.

Use of talc/talcum powder: Some research has suggested that the use of talc or talcum powder, when applied to sanitary napkins, diaphragms, condoms, or directly to the genitals, increases a woman’s risk for ovarian cancer. According to the American Cancer Society, many talcum powders in the past were contaminated with asbestos, which may explain the increase in ovarian cancer risk. However, until further research is conducted, women should avoid using talcum powder on the genital area. Cornstarch powders, which have not been linked to ovarian cancer, can be substituted instead.

Use of estrogen replacement therapy: Studies have shown that the long-term use of estrogen replacement therapy (ERT, estrogen without progesterone) may increase the risk of ovarian cancer. In a study of more than 200,000 women who took ERT for over 10 years, 944 deaths from ovarian cancer were recorded over a 14-year follow-up period. The researchers found that using ERT for 10 or more years doubled the risk of developing ovarian cancer (from 1% to 2%). Hormone replacement therapy has also been found to increase the risk of breast cancer in some women. However, because hormone replacement therapy can provide benefits (such as relief from menopausal symptoms, prevention of osteoporosis, and possible protection from heart disease), women should discuss the benefits and risks of taking hormone replacement therapy with their physician, based on their individual medical circumstances. Learn more about hormone replacement therapy.