Ovarian Cancer Awareness

Risk Factors

A risk factor is something that may increase the chance of developing a disease. But risk factors don't tell us everything. Having a risk factor, or even several risk factors, does not mean that you will get the disease. And many people who get the disease may not have had any known risk factors.

The following risk factors may increase the risk of ovarian cancer:

The risk of developing ovarian cancer gets higher with age. Ovarian cancer is rare in women younger than 40. Most ovarian cancers develop after menopause. Half of all ovarian cancers are found in women over the age of 63.

Various studies have looked at the relationship of obesity and ovarian cancer. Overall, it seems that obese women (those with a body mass index of at least 30) have a higher risk of developing ovarian cancer.

Reproductive history
A woman who has had children has a lower risk of ovarian cancer than women who have no children. The risk goes down with each pregnancy. Breast feeding may lower the risk even further. Using oral contraceptives (also known as birth control pills or "the pill') significantly lowers the risk of ovarian cancer if taken for longer than 5 years.

Gynecologic surgery
Tubal ligation (having your "tubes tied") may reduce the chance of developing ovarian cancer by up to 67%. A hysterectomy (removing the uterus without removing the ovaries) also seems to reduce the risk of getting ovarian cancer by about one-third.

Fertility drugs
In some studies, researchers have found that using the fertility drug clomiphene citrate (Clomid) for longer than one year may increase the risk for developing ovarian tumors. The risk seemed to be highest in women who did not get pregnant while on this drug. If you are taking fertility drugs, you should discuss the potential risks with your doctor. However, women who are infertile may be at higher risk (compared to fertile women) even if they don't use fertility drugs. This may be in part because they haven't had children or used birth control pills (which are protective). More research to clarify these relationships is now underway.

Androgens are male hormones. Danazol, a drug that increases androgen levels, was linked to an increased risk of ovarian cancer in a small study. In a larger study, this link was not confirmed, but women who took androgens were found to have a higher risk of ovarian cancer. Further studies of the role of androgens in ovarian cancer are planned.

Estrogen therapy and hormone therapy
Some recent studies suggest women using estrogens after menopause have an increased risk of developing ovarian cancer. The risk seems to be higher in women taking estrogen alone (without progesterone) for many years (at least 5 or 10). The increased risk is less certain for women taking both estrogen and progesterone.

Family history of ovarian cancer, breast cancer, or colorectal cancer
Ovarian cancer can run in families. Your ovarian cancer risk is increased if your mother, sister, or daughter has (or has had) ovarian cancer. The risk also gets higher the more relatives you have with ovarian cancer. Increased risk for ovarian cancer does not have to come from your mother's side of the family -- it can also come from your father's side. Up to 10% of ovarian cancers result from an inherited tendency to develop the disease. Genetic counseling, genetic testing, and strategies for preventing ovarian cancer in women with an increased familial risk.

Personal history of breast cancer
If you have had breast cancer, you may also have an increased risk of developing ovarian cancer. There are several reasons for this. Some of the reproductive risk factors for ovarian cancer may also affect breast cancer risk. The risk of ovarian cancer after breast cancer is highest in those women with a family history of breast cancer. A strong family history of breast cancer may be caused by an inherited mutation in the BRCA1 or BRCA2 genes. These mutations can also cause ovarian cancer.

Source: American Cancer Society What are the risk factors for ovarian cancer?.

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