Testing BRCA 1-2 Mutations in Metastatic Prostate Cancer: Results of a Survey of the Italian Association of Medical Oncology.

Background: 20% of prostate cancer (PC) patients harbor germinal or somatic alterations in homologous recombination repair (HRR) genes, including BRCA1/2. BRCA mutations represent predictive biomarkers for treatment with polyadenosine diphosphate-ribose inhibitors (PARPi). Olaparib has shown efficacy in metastatic castration-resistant PC (mCRPC) and is currently approved in Italy for mCRPC with BRCA1/2 mutations. National and international guidelines strongly recommend BRCA testing in PC. However, genetic testing presents challenges in clinical practice that may limit access to PARPi.

Methods: we conducted a survey directed towards members of the Italian Association of Medical Oncology to highlight the level of implementation of national recommendations and issues associated with genetic testing. Through an anonymous questionnaire, the survey collected clinical data of PC patients undergoing BRCA testing and the main difficulties to face in conducting the analysis.

Results: The survey was completed by 108 participants (5% of AIOM members). 52.8% of respondents test BRCA in all metastatic PC patients. If tissue analysis is invalid, only 17% use liquid biopsy, and 15.7% always consider a re-biopsy of a metastatic lesion. A quarter of respondents have to outsource genetic testing to another center and 17.6% have a split process between different institutions. Long timelines, lack of a predefined procedure, and unavailability of liquid biopsy represent the main issues based on respondents' opinions.

Conclusions: BRCA testing in PC still presents several difficulties in clinical practice that can limit access to PARPi treatment. Better implementation of molecular testing to identify BRCA-mutated patients is crucial for tailored treatment in mCRPC.