Ovarian Cancer: Risk Factors


Factors that may reduce a woman’s risk of developing ovarian cancer include the following.


The most important risk factor for developing ovarian cancer is increasing age. The disease most often occurs in women over 50 years of age. The risk to develop ovarian cancer by the age of 70 is about 1.4 percent.

Family History

Ovarian cancer risk increases for women who have a first-degree relative (mother, daughter and/or sister) with ovarian cancer. The risk is increased when two or more such relatives have a diagnosis of ovarian cancer. The risk to develop ovarian cancer when first degree relatives are affected is up to 5 percent.


About 12 percent of epithelial ovarian cancers develop in patients with a genetic predisposition. There are a number of mutations within the DNA of each cell of a woman’s body that can increase the risk significantly. Mutations are changes in the DNA of certain genes and might lead to loss of function of the gene that usually suppresses tumor growth.

For ovarian cancer, mutations in the BRCA1 or BRCA2 genes are particularly important since they are associated with increased risk of ovarian cancer. The risk to develop ovarian cancer with BRCA1 mutations is about 45 percent, with BRCA2 mutations about 25 percent. Another genetic syndrome is called hereditary non-polyposis colorectal cancer (HNPCC) which involves a different set of genes and is associated with an about 12 percent risk of developing ovarian cancer.


Women of North American, Northern European or Ashkenazi Jewish heritage are at increased risk for ovarian cancer.

Reproductive History

Women who have never had children, have unexplained infertility (the inability to bear children) or had their first child after the age of 30 are at increased risk for ovarian cancer. Also, women who started menstruation before age 12 and/or go through menopause later in life are at increased risk for ovarian cancer.


Fertility drugs may be associated with a higher risk of developing ovarian cancer, but most of these cases are a more benign category of ovarian cancers called borderline tumors with a usually good prognosis.