AUTHOR=Inci Alp , Witzel Isabell , Moch Holger , Rahmani-Khajouei Sepehr , Zoche Martin , Samartzis Eleftherios Pierre 

TITLE=Comprehensive genomic profiling for homologous recombination deficiency guides PARP inhibitor therapy recommendations in ovarian cancer

JOURNAL=Pathology and Oncology Research

VOLUME=Volume 31 - 2025

YEAR=2025

URL=https://www.por-journal.com/journals/pathology-and-oncology-research/articles/10.3389/pore.2025.1612266

DOI=10.3389/pore.2025.1612266

ISSN=1532-2807

ABSTRACT=ObjectiveTo evaluate the technical performance and clinical integration of FoundationOne®CDx (F1CDx) for high-grade serous ovarian cancer (HGSOC), focusing on its role in guiding PARP inhibitor (PARPi) therapy recommendations in a tertiary oncology center.MethodsWe conducted a retrospective analysis of 178 F1CDx tests performed on 168 HGSOC patients with unknown BRCA mutation status between January 2019 and August 2024. Molecular findings, including BRCA1/2 mutations, homologous recombination deficiency (HRD) status, loss of heterozygosity (LOH) scores, and HRR-related gene alterations, were correlated with tumor board recommendations and decisions for PARPi therapy. Laboratory turnaround time (TAT), assay performance, and integration into clinical workflows were assessed.ResultsThe F1CDx assay successfully generated comprehensive molecular profiles in 174 samples, with minimal limitations due to computational tumor content or inconclusive HRD readout. BRCA1/2 mutations were detected in 13.1% of patients, and 39.5% of tumors were HRD-positive (LOH ≥16%). In the internal cohort, 81.8% of patients received PARPi therapy recommendations, all directly informed by F1CDx results. PARPi selection differed by HRD status, with niraparib favored in HR-proficient and olaparib in HRD-positive tumors. The mean laboratory TAT was 8.4 days (standard deviation ±3.8), with 92.2% of tests completed within 14 days. No additional profiling was required for PARPi therapy recommendation, and no incidental findings beyond the scope of HRD testing were detected.ConclusionMolecular profiling with F1CDx proved to be a technically feasible, clinically impactful, and time-efficient assay, demonstrating its value in supporting molecular-guided PARPi therapy recommendations in the routine care of HGSOC patients.