Genetic History Adds to Risk of Ovarian Cancer

By Audrey P. Garrett, MD, MPH

One of the major risk factors for ovarian cancer is a family history of ovarian cancer. Women who have a mother, daughter or sister with ovarian cancer may be at increased risk, especially if their family risk is related to a genetic mutation in one of the genes known to be related to breast or ovarian cancer (known as BRCA1 and 2). Also, some women with a family history of cancer of the breast, uterus or colon may carry a different genetic mutation that may also put them at a slightly increased risk of ovarian cancer as well as a significantly increased risk of endometrial cancer.

If several women in a family have ovarian or breast cancer, especially at a young age, this may be considered a strong family history. If you have a strong family history of ovarian or breast cancer, you may want to talk with a genetic counselor. The counselor may recommend genetic testing for you or other women in your family. These tests can sometimes reveal gene changes that significantly increase ovarian cancer risk.

Women who have inherited certain altered (mutated) genes have a greatly increased risk of developing ovarian cancer. It may be as high as a 60% lifetime risk if you have mutations in the BRCA1 or BRCA2 genes. While very rare in the general population, these mutations are found in 2.5% of those of Ashkenazi Jewish descent.

Sometimes women with a very strong family history of ovarian cancer decide to have their ovaries and fallopian tubes removed as a precautionary measure. Known as a prophylactic (preventive) oophorectomy (removal of both ovaries) and salpingectomy (removal of the fallopian tubes), the surgery greatly reduces the risk of ovarian cancer in women who have inherited an altered version of the BRCA1 or BRCA2 genes; the surgery can also reduce their risk of breast cancer by as much as 50%. With prophylactic removal of the ovaries, there is still a small chance that ovarian-like cancer may develop.

It’s important to have a cancer risk assessment and counseling before making this decision. Obvious risks of prophylactic oophorectomy include loss of fertility. Other potential risks include hot flashes, altered libido, vaginal dryness, bone loss and increased risk of heart disease. As with any surgery there are risks involved with the actual procedure itself and it is important to weigh the risks and benefits for your particular situation.

While genetic mutations can confer a high risk of ovarian cancer, there are other risk factors that have been linked epidemiologically to ovarian cancer. The theory of “incessant ovulation” (i.e., women who have ovulated without a break like pregnancy or birth control pills) has been linked to ovarian cancer; women who have taken the pill (and thus not ovulated during that time period) can decrease their risk of ovarian cancer by as much as 50%.

Having a risk factor certainly doesn’t mean that a woman will get ovarian cancer. Most women with risk factors don’t get ovarian cancer and 90% of women who do get the disease have no known risk factors. If you think you may be at risk for ovarian cancer, be sure to talk with your doctor.

September is National Ovarian Cancer Awareness Month. To learn more about causes, prevention, detection and treatment of ovarian cancer, visit