Barcelona, Spain (UroToday.com) Despite significant progress in systematic therapy, metastatic castration-resistant prostate cancer (mCRPC) continues to be a lethal disease. mCRPC is molecularly heterogeneous, as up to 30% of mCRPC harbor deleterious alterations in DNA damage repair genes, including those with direct and indirect roles in homologous recombination repair. These loss-of-function alterations in homologous recombination repair genes are associated with response to PARP inhibition, of which BRCA1, BRCA2, and ATM are the most well characterized.