Role of genetic polymorphisms and ovarian cancer susceptibility

The value of identifying women with an inherited predisposition to epithelial ovarian cancer has become readily apparent with the identification of the BRCA1, and BRCA2 genes. Women who inherit a deleterious mutation in either of these genes have a very high lifetime risk of ovarian cancer (10-60%) and to some extent, increased risks of fallopian tube and peritoneal cancer. These highly lethal cancers are almost completely prevented by prophylactic salpingoophorectomy. BRCA1/2 mutation testing has become the accepted standard of care in families with a strong history of breast and/or ovarian cancer. This approach has the potential to reduce ovarian cancer mortality by about 10%. Although the ability to perform genetic testing for BRCA1 and 2 represents a significant clinical advance, the frequency of mutations in these high penetrance ovarian cancer susceptibility genes is low in most populations. There is evidence to suggest that ovarian cancer susceptibility might be affected by common low penetrance genetic polymorphisms like it was shown for several common disorders like diabetes or breast cancer. Although such polymorphisms would increase risk to a lesser degree, they could contribute to the development of a greater proportion of ovarian cancers by virtue of their higher frequencies in the population. It has been shown that the most powerful approach to studying low penetrance genes is an association study rather than a linkage study design. This review describes the efforts that have been made in this field by individual case-control studies and through multi-center collaborations as part of international consortia such as the Ovarian Cancer Association Consortium (OCAC).