Relevance of poly (ADP-ribose) polymerase inhibitors in prostate cancer.

PURPOSE OF REVIEW: Poly (ADP-ribose) polymerase inhibitors (PARPi) are approved drugs for the treatment of ovarian and breast cancer and currently under investigation for the treatment of prostate cancer and other malignancies with aberrations in homologous recombination DNA repair.This review summarizes literature published during 2017 concerning the relevance of PARPi in prostate cancer and presents new evidence on mechanisms of resistance and biomarkers of response.

RECENT FINDINGS: The approval of several PARPi (olaparib, rucaparib, and niraparib) has driven the focus of anticancer treatment on synthetic lethality in prostate cancer too. Despite anecdotal reports of long-term responders, most cancers become resistant to these therapies.Different mechanisms of primary and acquired resistance to PARPi have been recently investigated including loss of PARP1 expression, BRCA mutations with partial function, and acquisition of reversion restoration of function mutations.

SUMMARY: Here, we discuss the importance of PARPi in metastatic castration-resistant prostate cancer and discuss the possible mechanisms of resistance.