The Effect of Metformin in Patients With Metastatic Castration-resistant Prostate Cancer

Metastatic castration-resistant prostate cancer (mCRPC) can be treated with ADT plus abiraterone, ADT plus enzalutamide, ADT plus cabazitaxel, ADT plus docetaxel, ADT plus olaparib. However, patients have short overall survival after progression to CRPC, although multiple options are available for mCRPC. Therefore, there is still a need to improve the therapeutic effect for mCRPC. Many studies have shown that metabolic syndrome and its components are associated with increased development and progression of aggressive prostate cancer. Metformin, a common well-tolerated oral biguanide prescribed for type II diabetes, could be used to decrease the risk of prostate cancer development and improve the efficacy of treatment. Some studies reported that metformin could enhance the effectiveness of ADT, and improve recurrence-free survival, overall survival and cancer-specific survival. A prospective randomized study reported that metformin potentially lengthen time to CRPC in advanced prostate cancer patients when combined with ADT especially in those with high risk localized prostate cancer, clinically node positive and in those with low tumor volume metastatic hormone-sensitive patients. After extensive research, there is no published results from prospective randomized trials evaluating the effect of metformin in combination with ADT and abiraterone among patients with mCRPC.