Intra-abdominal carcinomatosis after prophylactic oophorectomy in women of hereditary breast ovarian cancer syndrome kindreds associated with BRCA1 and BRCA2 mutations.

Objective: Prophylactic surgical removal of the ovaries has been offered for many years as a potential preventative of ovarian cancer in women deemed to be at increased hereditary risk for this disease. Now, it is possible to test for specific mutations of the BRCA1 and BRCA2 genes that render members of hereditary breast ovarian cancer (HBOC) syndrome families susceptible to cancer. Widespread intra-abdominal carcinomatosis, which mimics metastatic ovarian serous carcinoma, has been reported following oophorectomy in individuals at increased hereditary risk. This study was undertaken to examine and report particularly the occurrence of intra-abdominal carcinomatosis, as well as other cancers, following prophylactic oophorectomy in patients who carry cancer susceptibility mutations of BRCA1 and BRCA2 and to assess the cumulative risks for this disease in order to assist in developing appropriate surgical interventions, based on currently available information, and to counsel patients who choose prophylactic surgery, concerning the potential prognosis, thereafter.

Methods: The Creighton University Hereditary Cancer Institute registry was searched for members of HBOC syndrome families who had undergone prophylactic oophorectomy. The histories and results of DNA testing for the BRCA1 and BRCA2 mutations carried in their families were recorded, tabulated and examined, and the aggregate data are reported along with pertinent details of those individuals who developed neoplastic diseases after prophylactic oophorectomy. All available histologic and cytologic materials of patients who were diagnosed with intra-abdominal carcinomatosis were reviewed, and life-table calculations were performed to assess cumulative risks for this disease following prophylactic oophorectomy.

Results: From 72 HBOC syndrome families that carried either BRCA1 or BRCA2 cancer-associated mutations, 238 individuals who had undergone prophylactic oophorectomy were recorded in our registry between January 1985 and December 2002. During a mean follow-up of 9.3 years, cancers were diagnosed in 27 subjects, including 16 individuals with breast cancer and five patients with intra-abdominal carcinomatosis. Breast cancers were stage I in 10 of 12 proven carriers of cancer-associated mutations. All five cases of intra-abdominal carcinomatosis were serous carcinomas, and all occurred in BRCA1 mutation carriers. Histologic review of the prophylactically removed ovaries found borderline lesions in two cases, one with possible early stromal invasion. Two of the five patients who developed intra-abdominal carcinomatosis were among 78 patients in this series who were diagnosed and treated for breast cancer before prophylactic oophorectomy. A 3.5% cumulative risk for all mutation carriers and a 3.9% cumulative risk for BRCA1 mutation carriers were calculated through 20 years of follow-up after prophylactic oophorectomy.

Conclusions: Intra-abdominal carcinomatosis in our series was diagnosed only in BRCA1 mutation carriers. The calculated cumulative risks of developing intra-abdominal carcinomatosis after prophylactic oophorectomy in members of HBOC syndrome families, specifically those who carry deleterious mutations, are well below the estimated risks of ovarian cancer published in the literature for similar patients. Breast cancers, which tended to be small and localized, were the most common malignancy in BRCA1 and BRCA2 mutation carriers after prophylactic oophorectomy.