Ovarian cancer causes and risk factors

This page was reviewed under our medical and editorial policy by

Maurie Markman, MD, President, Medicine & Science

This page was updated on July 8, 2022.

What causes ovarian cancer?

While the exact cause of ovarian cancer may not be known, several factors may increase the risk of developing the disease. The likelihood of developing the disease may be higher if a woman has one or more ovarian risk factors. One key risk factor is age. Most women who develop ovarian cancer are diagnosed after menopause, at age 55 or older, though patients in their 40s and 50s have also been diagnosed with the disease.

If you have a strong family history of breast cancer or ovarian cancer, you may also be at an increased risk. Talk to your doctor about genetic counseling, genetic testing and other steps you may be able to take to monitor or reduce your ovarian cancer risk, such as preventive surgery.

This article will cover:

Ovarian cancer risk factors

Some common risk factors for ovarian cancer include:


Age: Two-thirds of women diagnosed with ovarian cancer are 55 or older.


Family history: Women with a mother, sister, grandmother or aunt who has had ovarian cancer have a higher risk of developing the disease.

Genetic mutations: Some women who develop ovarian cancer have an inherited mutation on one of two genes called breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2). Women with the BRCA1 mutation have a 35 to 70 percent higher risk of ovarian cancer. Women with the BRCA2 mutation have a 10 to 30 percent higher risk. However, the vast majority of women who are diagnosed with ovarian cancer don’t have either mutation. If you are concerned about this risk factor for ovarian cancer, discuss getting tested for both BRCA mutations with your OB-GYN or a gynecologic oncologist.

Lynch syndrome and Peutz-Jeghers syndrome: Women who have these inherited genetic disorders have a higher risk of developing ovarian cancer. Lynch syndrome is characterized by a higher risk of cancers of the digestive tract, gynecologic tract and other organs. Peutz-Jeghers syndrome indicates an increased risk of developing polyps in the digestive tract and several types of cancer, including in the breast, colon, rectum, pancreas, stomach, testicles, ovaries, lungs and cervix.

Previous conditions

Breast, colorectal or endometrial cancer: Women who have been diagnosed with these cancers have a higher risk of developing ovarian cancer.

Factors that may lower the risk of ovarian cancer

Factors that may lower the risk of ovarian cancer include:

Childbearing status: Women who have delivered at least one child, especially before age 30, are at a lower risk of developing the disease. The more children a woman has, the more her ovarian cancer risk declines. Women who breastfeed further reduce their risk.

Birth control: Women who have used oral contraceptives for at least three months are at a lower risk of ovarian cancer. The risk is lower the longer the contraceptives are taken. The lower risk continues for many years after contraceptives are stopped.

Gynecologic surgery: A tubal ligation (tying the fallopian tubes) or hysterectomy (removing the uterus but not the ovaries) reduces the risk of developing ovarian cancer.

Next topic: What are the symptoms of ovarian cancer?

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