Homologous recombination deficiency tumor tissue testing in a real-world cohort of tubo-ovarian carcinoma patients: validation of decentralized genomic profiling in 4777 cases

High-grade tubo-ovarian carcinoma (HGOC) that exhibits homologous recombination deficiency (HRD) comprises almost half of these tumors and shows a greater response to platinum-based chemotherapies and a sensitivity to PARP inhibitors. Therefore, experts believe that tumor testing for HRD should be carried out at the time of primary diagnosis or disease recurrence, if not performed earlier. This study aimed to evaluate HRD in a large series of patients with HGOC via the centralized Myriad MyChoice CDx and the decentralized SOPHiA Genetics DDM HRD Solution assays in a real-world clinical practice in Spain. With the Myriad MyChoice CDx Plus assay, 502 (38%) of the 1322 tumor samples analyzed were categorized as HRD positive; overall, 198 (15%) cases were not informative. With the decentralized SOPHiA Genetics DDM HRD assay, 1876 (39%) of the 4777 tumor tissue samples analyzed were HRD positive; of the 4777 cases, 606 (13%) were non-informative. The HRD and mutational status results for all cases were reported to clinicians from participant laboratories in less than 21 working days using the SOPHiA Genetics DDM HRD assay. This study shows that a decentralized HRD test, such as the SOPHiA Genetics DDM HRD Solution assay, is a reliable and robust assay to provide therapeutic guidance for ovarian cancer patient management in clinical practice, with optimal performance in terms of an informative proportion of cases, positive HRD detection, and an adequate turnaround time.