Ovarian cancer can be hereditary. The chance that ovarian cancer is hereditary depends on the type of ovarian cancer. In general, for women with a diagnosis of HGSC, there is a 20% chance that the cancer is hereditary. This means that there is an 80% chance that the cancer is not hereditary.
BRCA1 and BRCA2
The genes known to increase a woman’s risk of developing HGSC are the breast cancer susceptibility genes 1 and 2, referred to as BRCA1 and BRCA2. The overall lifetime risk for developing ovarian cancer is 20-40% for women who have a BRCA1 mutation and 10-20% for women who have a BRCA2 mutation. Women in the general population have less than 2% risk of developing ovarian cancer.
A woman with a first-degree relative (a mother, sister or daughter) with a known BRCA1 or BRCA2 gene mutation has a 50% chance of having the same mutation. Click to learn more about the BRCA1 or BRCA2 genes.
Other risk genes
There are two other groups of genes that may increase risk for ovarian cancer. These genes belong to the mismatch repair and the Fanconi Anemia pathways, which are involved in repair of damaged DNA.
A woman with a mutation in a mismatch repair gene has up to a 12% risk to develop ovarian cancer in her lifetime. These mutations are usually found in non-serous ovarian cancers, including endometrioid or clear cell cancers. Women with mismatch repair gene mutations also have an increased risk for other cancers such as colon cancer (large intestine) and endometrial cancer (part of the uterine lining). Women who inherit a mismatch repair gene mutation have a condition called Lynch syndrome. Specific cancer screening, such as a colonoscopy, can prevent or catch the early stages of Lynch syndrome-associated cancers.
The risk of ovarian cancer from Fanconi Anemia pathway gene mutations is still being studied; but scientific data so far shows up to a 10% lifetime risk of developing ovarian and breast cancers in women with mutations in some of these genes. Mutations in the Fanconi Anemia pathway genes are seen at all ages of diagnosis and in all five types of ovarian cancer, including HGSC.