Survival Benefit of Germline BRCA Mutation is Associated with Residual Disease in Ovarian Cancer

Background/Aims: Prognostic value of germline BRCA1 or BRCA2 (gBRCA1/2) mutations in epithelial ovarian cancer (EOC) remains controversial, especially in the estimation of long-term survival. We previously reported the largest study of gBRCA1/2 mutation prevalence in Chinese EOC patients. The aim of this study is to further illustrate the correlation of residual disease and survival in BRCA-associated EOC in China. Methods: In the current cohort consisting of 615 cases from the Chinese EOC genome-wide association study, we evaluated the association between gBRCA1/2 mutation and clinical outcomes. Results: Overall, we did not find any significant difference between gBRCA1/2 mutation carriers and non-carriers in both progression-free survival (PFS) and overall survival (OS) (19.3 vs. 18.1 months and 77.2 vs. 73.2 months, P=0.528 and 0.147, HR 0.93 and 0.79, 95%CI 0.74-1.17 and 0.57-1.09, respectively). However, within three years after diagnosis, mutation carriers showed a longer OS than non-carriers (P=0.018, HR 0.53, 95%CI 0.31-0.90). Such a survival advantage decreased along with the extension of follow-up time. Quite interestingly, in the subgroup of patients with gross residual disease, mutation carriers had a longer survival than non-carriers (18.5 vs. 15.1 months and 68.5 vs. 54.3 months, P=0.046 and 0.038, HR 0.74 and 0.65, 95% CI 0.55-1.00 and 0.43-0.98, for PFS and OS respectively). Conclusions: Our findings provided the evidence that gBRCA1/2 mutation was not associated with survival in Chinese EOC patients, which possibly attributed to more than 37% of the patients without gross residual disease. Survival benefit of gBRCA1/2 mutation was prominent in ovarian cancer patients with gross residual disease.