Mutations in Homologous Recombination Genes and Outcomes in Ovarian Carcinoma Patients in GOG 218: An NRG Oncology/Gynecologic Oncology Group Study

Purpose: We hypothesized that mutations in homologous recombination repair (HRR) genes beyond BRCA1 and BRCA2 improve outcomes for ovarian carcinoma patients treated with platinum therapy and would impact the relative benefit of adding prolonged bevacizumab.

Experimental Design: We sequenced DNA from blood and/or neoplasm from 1,195 women enrolled in GOG-0218, a randomized phase III trial in advanced ovarian carcinoma of bevacizumab added to carboplatin and paclitaxel. Defects in HRR were defined as damaging mutations in 16 genes. Proportional hazards models were used to estimate relative hazards for progression-free survival (PFS) and overall survival (OS).

Results: Of 1,195 women with ovarian carcinoma, HRR mutations were identified in 307 (25.7%). Adjusted hazards for progression and death compared with those without mutations were lower for women with non-BRCA HRR mutations [HR = 0.73; 95% confidence interval (CI), 0.57–0.94; P = 0.01 for PFS; HR = 0.67; 95% CI, 0.50–0.90; P = 0.007 for OS] and BRCA1 mutations (HR = 0.80; 95% CI, 0.66–0.97; P = 0.02 for PFS; HR = 0.74; 95% CI, 0.59–0.94; P = 0.01 for OS) and were lowest for BRCA2 mutations (HR = 0.52; 95% CI, 0.40–0.67; P < 0.0001 for PFS; HR = 0.36; 95% CI, 0.25–0.53; P < 0.0001 for OS). A test of interaction showed no difference in the effect of bevacizumab on PFS between cases with and without mutations.

Conclusions: HRR mutations, including non-BRCA genes, significantly prolong PFS and OS in ovarian carcinoma and should be stratified for in clinical trials. The benefit of adding bevacizumab was not significantly modified by mutation status. Clin Cancer Res; 24(4); 777–83. ©2017 AACR.

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