Abstract
INTRODUCTION: Homologous recombination deficiency (HRD) is a key biomarker in the management of high-grade serous ovarian cancer (HGSOC), guiding treatment decisions, particularly regarding the use of poly(ADP-ribose) polymerase inhibitors (PARPi). As multiple HRD assays are available, each with distinct methodologies and cutoff values, the interpretation and clinical application of HRD testing remain complex. This intergroup statement, endorsed by the German Ovarian Cancer Commission, NOGGO, AGO Austria, and AGO Swiss, aims to provide guidance on the indications, appropriate use, and limitations of HRD testing in ovarian cancer. MATERIALS AND METHODS: The statement is based on an interdisciplinary review of available literature, clinical trial data, and expert consensus. The recommendations focus on the current landscape of HRD assays, their clinical applicability, and practical considerations regarding the optimal timing and indications for testing. RESULTS AND DISCUSSION: Various HRD assays, including established commercial tests and emerging academic-clinical approaches, are reviewed in this statement. The document outlines key eligibility criteria for HRD testing in ovarian cancer, emphasizing its relevance in specific histological subtypes and clinical scenarios. Additionally, exclusion criteria are defined, highlighting cases where HRD testing may not be appropriate due to insufficient clinical validation or lack of therapeutic implications. Finally, the statement discusses the pathological minimum requirements for tissue samples used in HRD testing, ensuring adequate sample quality and tumor content for reliable results. CONCLUSION: HRD testing is a valuable tool for personalizing ovarian cancer treatment, particularly in identifying patients who may benefit from PARPi therapy. However, assay selection, timing, and result interpretation require careful consideration. This statement provides a structured approach to optimize HRD testing, aiming to improve clinical decision-making and patient outcomes.