Epithelial ovarian cancer (EOC) is the most frequent form of OC, a disease with a poor prognosis and high lethality, as most patients are diagnosed at advanced stages. To successfully battle EOC, it is crucial to identify reliable biomarkers and use personalised therapies in patient subgroups. A common feature of high-grade serous and endometrioid OC is homologous recombination repair deficiency (HRD), which frequently stems from the inactivation of the breast cancer susceptibility (BRCA) genes. Poly-(adenosine diphosphate [ADP])-ribose polymerase inhibitors (PARPi) were, therefore, developed for their lethality against HRD tumour cells. While patients with non-HRD tumours may also benefit from PARPi therapy in the recurrent EOC setting, recent phase III trials on newly diagnosed advanced-stage EOC have shown that PARPi treatment benefit is greater in patients with HRD tumours. These findings open new avenues for the use of PARPi as maintenance therapy in HRD-positive patients who had received first-line chemotherapy. This manuscript provides recommendations for Belgian physicians on how to approach HRD testing and incorporate it into treatment decisions of patients with newly diagnosed advanced-stage EOC.

(BELG J MED ONCOL 2023;17(2):38–45)