Homologous recombination repair gene mutations show no survival benefits in Chinese high-grade serous ovarian cancer patients

Background: The purpose of our study was to identify germline and somatic homologous recombination repair (HRR) pathway gene mutations and their clinical-prognostic impact in Chinese high-grade serous ovarian cancer (HGSC) patients.

Methods: We applied next-generation sequencing (NGS) in consecutive patients who underwent primary surgery for HGSC in November and December 2015 at our institution. Paired peripheral blood (or para-carcinoma tissue) samples and tumor samples from 42 Chinese women were tested to identify both germline and somatic deleterious mutations through all exons in BRCA1/2 and 22 other core HRR genes. Clinic-pathological data were collected until February, 2020. Associations between HRR gene mutations and clinical characters and outcomes were also evaluated.

Results: Deleterious germline HRR mutations were identified in 16.7% (7/42) of the HGSC patients. One patient had both germline BRCA2 and ATM mutations. Six patients had only somatic mutations, increasing the HRR mutation rate to 31.0% (13/42). Neither germline nor somatic HRR gene mutations were related with residual disease (P=0.233) nor platinum sensitivity (P=0.851). In the univariate and multivariate analyses, germline HRR gene mutation status was not associated with progression-free survival (PFS) or overall survival (OS). In addition, no prognostic differences between somatic HRR mutated patients and wild-type patients were found.

Conclusions: Our results suggest that the HRR gene defect was not associated with improved survival in our Chinese HGSC patient cohort.