Up to 25 to 30 percent of metastatic prostate cancer patients have homologous recombination repair ( HRR ) genes mutated, including BRCA1 / 2, indicating a particular subgroup that may benefit significantly from targeted therapy with PARP inhibitors( PARPi ). In metastatic castration-resistant prostate cancer ( mCRPC ) patients, single-agent PARPi has been shown to be effective. To date, two major phase III clinical trials, the PROfound and the TRITON3, have reported a prolonged radiographic progression-free survival( rPFS ) and overall survival of olaparib and rucaparib, respectively, over physician’s choice control therapy in patients with BRCA1 / 2 mutations( BRCA1-2 +) [ 2, 3 ].