Homologous recombination deficiency test validation in patients with high-grade advanced ovarian cancer.

Background: Along with mutation status, homologous recombination deficiency (HRD) testing is a prognostic and predictive biomarker for poly-ADP-ribose polymerase (PARP) inhibitor therapy indication in high-grade epithelial ovarian, fallopian tube, or peritoneal cancer. Approximately 50% of high-grade serous ovarian cancers exhibit HRD, even in the absence of germline or somatic 1/2 loss-of-function mutations. In this scenario, access to a validated diagnostic HRD test can optimize treatment selection and increase the effectiveness of the intervention.