Ovarian Cancer Prevention (PDQ®): Prevention - Health Professional Information [NCI] - Description of the Evidence
The heterogeneity of ovarian cancer and the suggestion of different molecular pathways of origin for cancer subtypes present challenges and opportunities for the conduct and interpretation of etiologic factors associated with the development of ovarian cancer. Etiologic association may vary by the mix of subtypes in the populations included in the epidemiologic studies. Ovarian cancer is a rare cancer, thus sample size and power of studies to detect moderate association by subtype of cancer are limited. However, clearer subtyping of cancers may assist is improving our understanding of the etiology of ovarian malignancies in future studies.
Inherited Susceptibility to Ovarian Cancer
Some women are at an increased risk because of an inherited susceptibility to ovarian cancer, with the magnitude of that risk depending on the affected gene and specific mutation. Underlying ovarian cancer risk can be assessed through accurate pedigrees and/or genetic markers of risk. Because of uncertainties about cancer risks associated with specific gene mutations, genetic information may be difficult to interpret outside of families with a high incidence of ovarian cancer. The following three inherited ovarian cancer susceptibility syndromes have been described: (1) familial site-specific ovarian cancer; (2) familial breast/ovarian cancer; and (3) Lynch II syndrome, which is a combination of breast, ovarian, endometrial, gastrointestinal, and genitourinary cancers.[3,4] Considering family history in the absence of specific information on BRCA1/2 mutation status, unaffected women who have two or three relatives with ovarian cancer have a cumulative ovarian cancer risk of about 7%.[3,5] Women who have a mother or sister with ovarian cancer have a cumulative lifetime risk of ovarian cancer of about 5%.
Multiple genetic syndromes are not addressed in this summary. This summary also does not address women who are at high risk because of inherited genetic factors. (Refer to the Oral contraceptives section in the PDQ summary on Genetics of Breast and Ovarian Cancer and the PDQ summary on Genetics of Colorectal Cancer for specific information related to ovarian cancer risk associated with multiple genetic syndromes and ovarian cancer in BRCA1/2 mutation carriers.)