Abstract
Women with a deleterious mutation in the BRCA1 or BRCA2 gene have a high lifetime risk of ovarian cancer (range, 15%-54%).1-5 Mutations in either of these genes increase susceptibility to cancers of the ovary, fallopian tube, and peritoneum. It is difficult to distinguish between these 3 forms of cancer because the clinical symptoms are similar and because the pathological appearance of the 3 tumor types is almost identical. It is important to generate risk estimates separately for peritoneal cancer for BRCA1 and BRCA2 carriers after oophorectomy because this end point is an indicator of the effectiveness of preventive surgery. The level of cancer risk reduction associated with prophylactic oophorectomy has been estimated to be as high as 95%. However, most of the studies to date that have evaluated the risk of ovarian, peritoneal, and fallopian tube cancer have used either historical or cross-sectional designs,1-5 and these are subject to bias. In this prospective study, we estimate the absolute risks for developing ovarian, fallopian tube, and peritoneal cancers in an international cohort of BRCA1 and BRCA2 mutation carriers. The risk reduction associated with prophylactic salpingo-oophorectomy is then estimated after adjustment for a number of cofactors.