Concordance between Three Homologous Recombination Deficiency (HRD) Assays in Patients with High-Grade Epithelial Ovarian Cancer

Simple Summary In patients with epithelial ovarian cancer, the gold standard Myriad MyChoice (R) CDx assay is used to assess homologous recombination deficiency (HRD), as a biomarker predicting benefit from a targeted treatment, poly (ADP-ribose) polymerase inhibitors (PARPi). Having multiple available assays to identify patients with HRD-positive tumors is critical to ensure sufficient diagnostic capacity across different countries, and to provide greater variety for clinicians and diagnostic laboratories. Our aim was to evaluate the concordance between Myriad MyChoice and two alternative HRD assays (AmoyDx HRD Focus NGS Panel and OncoScan (TM)) in patients with epithelial ovarian cancer. In the same tumor tissue samples that were previously assessed with the Myriad MyChoice (R) CDx assay, the two alternative platforms evaluated HRD status in a blinded manner. Indeed, our study demonstrated high concordance between the Myriad MyChoice assay and each assay under evaluation, thus providing alternative options for HRD testing.Abstract Our aim was to evaluate the concordance between the Myriad MyChoice and two alternative homologous recombination deficiency (HRD) assays (AmoyDx HRD Focus NGS Panel and OncoScan (TM)) in patients with epithelial ovarian cancer (EOC). Tissue samples from 50 patients with newly diagnosed EOC and known Myriad MyChoice HRD status were included. DNA aliquots from tumor samples, previously evaluated with Myriad MyChoice and centrally reassessed, were distributed to laboratories to assess their HRD status using the two platforms, after being blinded for the Myriad MyChoice CDx HRD status. The primary endpoint was the concordance between Myriad MyChoice and each alternative assay. Tumor samples were evaluated with an AmoyDx (R) HRD Focus Panel (n = 50) and with OncoScan (TM) (n = 43). Both platforms provided results for all tumors. Analysis showed that correlation was high for the Myriad MyChoice GI score and AmoyDx (R) HRD Focus Panel (r = 0.79) or OncoScan (TM) (r = 0.87) (continuous variable). The overall percent agreement (OPA) between Myriad MyChoice GI status (categorical variable) and each alternative assay was 83.3% (68.6-93.3%) with AmoyDx and 77.5% (61.5-89.2%) with OncoScan (TM). The OPA in HRD status between Myriad MyChoice and AmoyDx was 88.6% (75.4-96.2). False-positive rates were 31.6% (6/19) for AmoyDx GI status and 31.9% (7/22) for OncoScan (TM), while false-negative rates were 0% (0/28, AmoyDx) and 11.1% (2/18, OncoScan (TM)) compared with the Myriad MyChoice GI status. While substantial concordance between Myriad MyChoice and alternative assays was demonstrated, prospective validation of the analytical performance and clinical relevance of these assays is warranted.