What is the genetic basis for an increased risk of ovarian cancer? How does it relate to risk for breast cancer?
Darcy Thull, MS: The majority of ovarian cancer occurs for reasons that are not completely understood. About 10% of the time ovarian cancer is the result of an underlying hereditary (genetic) susceptibility. The susceptibility results from inheriting a nonfunctioning gene. Mutations (genetic changes) in either of two genes, BRCA1 and BRCA2, account for most of the genetic risk for ovarian cancer. Everyone, men and women alike, have two copies of each of the BRCA1 and BRCA2 genes. One copy of each is inherited from our mother and the other from our father, which means that a nonworking copy of the gene can be passed from either parent. These genes usually play a role in preventing tumors from forming; however if either of the genes does not work due to a mutation, it cannot do its job, and there is an increased risk for cancer to develop. Inheriting a nonfunctioning copy of one of these genes primarily increases the risk for ovarian and breast cancers, though the exact reasons for this
