Homologous recombination deficiency in epithelial ovarian cancers: from molecular characterization to patient journey

Abstract

High-grade serous ovarian carcinoma (HGSOC), the most frequent and aggressive form of epithelial ovarian cancer is characterized in half of cases by homologous recombination deficiency (HRD). This molecular alteration is defined by distinct causes and consequences. The main and most characterized cause is the presence of an alteration affecting BRCA1 and BRCA2 genes. Regarding consequences, a specific genomic instability leads to increased sensitivity to platinum salts and poly (ADP-ribose) polymerase (PARPi) inhibitors. This latter point enabled the advent of PARPi in first and second line maintenance. As such, the initial and rapid evaluation of HRD status with molecular tests is a key step in the management of HGSOC. Until recently, the range of tests offered proved to be very limited and suffered from technical and medical limitations. This has recently led to the development and validation of alternatives, including academic ones. This "state of the art" review will bring a synthesis concerning the assessment of HRD status in HGSOCs. After a brief introduction of HRD (including main causes and consequences) and of its predictive value regarding PARPi, we will discuss the limitations of current molecular tests and the existing alternatives. Finally, we will contextualize this to the situation in France, with special consideration concerning the positioning and the financial coverage of these tests, with the perspective of optimizing patient management .