Managing hereditary ovarian cancer risk.

Ovarian cancer is the fourth leading cause of cancer deaths in American women. About 10% of cases are thought to have a hereditary basis, and family history is the strongest known risk factor. In the past, prophylactic oophorectomy has been advocated for women with two or more affected first-degree relatives. More recently, with the identification of the genes responsible for most hereditary ovarian cancers (BRCA1, BRCA2), oophorectomy can now be offered specifically to women who are mutation carriers. Conversely, noncarriers in these families can be reassured that their risk of ovarian cancer is not increased. The value of oophorectomy in mutation carriers has not yet been proven, however, and concern exists that the benefit may be less than intuitively expected. First, although the lifetime risk of ovarian cancer initially was reported to be as high as 60%, more recent studies have suggested risks in the range of 15 to 30%. A better understanding of the factors that underlie variable penetrance in mutation carriers is needed to augment our ability to counsel individual women. In addition, peritoneal papillary serous carcinoma indistinguishable from ovarian cancer occurs in some women after oophorectomy. Studies that better define the frequency with which this occurs are needed to establish the magnitude of the protective effect conferred by prophylactic oophorectomy. In view of the uncertainty regarding the efficacy of prophylactic oophorectomy, chemopreventive and early detection approaches also deserve consideration as strategies for decreasing ovarian cancer mortality in women who carry mutations in ovarian cancer susceptibility genes.