Germline and Somatic BRCA1/2 Gene Mutational Status and Clinical Outcomes in Epithelial Peritoneal, Ovarian, and Fallopian Tube Cancer: Over a Decade of Experience in a Single Institution in Korea

This study aimed to present a single institutional experience with BRCA1/2 gene tests and the effects of pathogenic mutations in epithelial peritoneal, ovarian, and fallopian tube cancer (POFTC) on survival outcomes. We identified patients with epithelial POFTCs who underwent BRCA1/2 gene testing by either germline or somatic methods between March 2007 and March 2020. Based on the BRCA1/2 test results, patients were divided into BRCA mutation and wild-type groups, followed by comparisons of clinicopathologic characteristics and survival outcomes after primary treatment. The annual number of POFTC patients who received BRCA1/2 gene tests increased gradually. In total, 511 patients were included and BRCA1/2 mutations were observed in 143 (28.0%). Among 57 patients who received both germline and somatic tests, three (5.3%) showed discordant results from the two tests. Overall, no differences in progression-free survival (PFS; p=0.467) and overall survival (p=0.641) were observed between the BRCA mutation and wild-type groups; however, multivariate analyses identified BRCA1/2 mutation as an independent favorable prognostic factor for PFS (adjusted hazard ratio [aHR], 0.765; 95% confidence interval [CI], 0.593 to 0.987; p=0.040). In 389 patients with International Federation of Gynecology and Obstetrics stage III-IV, different results were shown depending on primary treatment strategy: while BRCA1/2 mutation significantly improved PFS in the subgroup of neoadjuvant chemotherapy (aHR, 0.619; 95% CI, 0.385 to 0.995; p=0.048), it did not affect patient PFS in the subgroup of primary debulking surgery (aHR, 0.759; 95% CI, 0.530 to 1.089; p=0.135). BRCA1/2 mutations are frequently observed in patients with epithelial POFTCs, and such patients showed better PFS than did those harboring wild-type BRCA1/2.