Homologous recombination deficiency testing in patients with high grade ovarian cancer: factors influencing test success

Abstract

Introduction: Testing for tumor BRCA mutations and homologous recombination deficiency (HRD) is recommended for all patients with advanced high-grade epithelial ovarian cancer. Delays in the HRD testing process can significantly affect the treatment offered to patients. Methods: HRD testing pathways and sampling processes were analyzed for tests sent from a tertiary gynae-oncology referral center between December 2020 and January 2023. Results: A total of 148 hRD tests were performed in 125 patients. The overall success rate of HRD testing was 69.6%. The success rates of obtaining results were: from diagnostic image-guided biopsy 66.7% (n = 40/60), at primary surgery 91.5% (n = 42/47), and at interval debulking surgery 51.2% (n = 21/41). The use of a larger 16-gauge needle used at image-guided biopsy produced a 100% success rate. Of 148 tests carried out, the median time for result was 28 days (range 14–158 days), with only 27% returned results in 21 or fewer days. In successful tests, 44.7% were classified as HRD-positive. 97% of patients with HRD-positive tumors treated at the center received a PARP inhibitor as part of their first-line maintenance treatment. Conclusions: By optimizing the factors affecting HRD test success, we can obtain faster results and offer patients appropriate treatment at earlier time points to improve patient outcomes.