Concordance of BRCA mutation detection in tumor versus blood, and frequency of bi-allelic loss of BRCA in tumors from patients in the phase III SOLO2 trial

•There are limited data on the concordance between tumor BRCA (tBRCA) and germline BRCA (gBRCA) testing in ovarian cancer.•In SOLO2, concordance between tBRCA and gBRCA testing was very high (98%) in gBRCA-mutated patients.•Large insertions or deletions accounted for only a small subset (5%) of gBRCA mutations.•The near 100% rate of bi-allelic loss of BRCA suggests that routine testing for BRCA zygosity is not required.•Results are in keeping with BRCA loss being a driver of tumorigenesis in ovarian cancer.