Risk-reducing appendectomy and the elimination of BRCA1-associated intraperitoneal cancer

Abstract

Risk-reducing bilateral salpingo-oophorectomy (RRBSO) and risk-reducing mastectomy are widely used for BRCA1 and BRCA2 mutation carriers to reduce the risk of ovarian and breast cancer. To our knowledge, no risk-reduction therapy has addressed the BCRA1/2 carrier lifetime risk of intra-abdominal peritoneal carcinoma from an appendix source. We identified a BRCA1 carrier in a hereditary breast and ovarian cancer kindred who developed a low-grade malignant appendiceal mucocele 2 years after risk-reducing salpingo-oophorectomy. Our retrospective meta-analysis assessed the risk of intraperitoneal appendiceal cancer in BRCA1/2 carriers after RRBSO to determine whether elective risk-reduction appendectomy could reduce the incidence of intraperitoneal cancer. Data sources included the case report and 12 reports of BRCA1 and BRCA2 carriers after RRBSO with ovarian, fallopian tube, breast, and peritoneal cancer published from January 1, 1985, through April 30, 2012. Main outcome measures were nonovarian, non-fallopian tube, nonbreast, positive intra-abdominal peritoneal carcinoma in previously cancer-free BRCA1/2 carriers after RRBSO. The source of intraperitoneal cancer in BRCA1/2 carriers after risk-reducing salpingo-oophorectomy is highly likely the appendix. Use of risk-reduction appendectomy with RRBSO in younger BRCA1/2 carriers may reduce lifetime risk of malignant tumor and eliminate intraperitoneal cancer.