Abstract: Objective：To evaluate the safety and efficiency of using abiraterone and prednisone in the treatment of patient with metastatic castration resistant prostate cancer (mCRPC) no prior chemotherapy. Methods: Three mCRPC no prior chemotherapy patients accepted abiraterone and prednisone treatment. The clinical data were analyzed retrospectively and the safety and efficiency of this treatment option were discussed. The Gleason scores of the three mCRPC patients were 5, 9, and 9. The clinical stages were T3aNxM0, T3aNxM1b, and T3aNxM1b. The patients received abiraterone 1 000 mg daily and prednisone 5 mg twice daily and androgen deprivation therapy in the treatment. Their blood pressure, complete blood count, prostate specific antigen (PSA), biochemical parameters, whole body CT scan and bone scan were done regularly to monitor the progression of the diseases. Results: In this study, the general condition improved in two patients. Two of the three patients experienced decrease of PSA and no progression. One patient experienced disease progression. Generally, abiraterone and prednisone resulted in prolonged radiographic progression-free survival and delayed in PSA progression in mCRPC no prior chemotherapy. There were no severe side effects, such as hypokalemia, hypertension, and water-sodium retention. The patient’s tolerance was good. Conclusion:Abiraterone and prednisone are safe and can improve mCRPC no prior chemotherapy patient’s life quality and may prolong the overall survival.

Key words: Neoplasms, hormone-dependent, Prostatic neoplasms, Abiraterone