A tertiary care audit of using abiraterone acetate in patients of metastatic castrate-resistant prostate cancer

INTRODUCTION: This is a retrospective analysis to assess the safety and efficacy of abiraterone acetate (AA) in metastatic castrate-resistant prostate cancer (mCRPC) patients treated at tertiary care institute. MATERIALS AND METHODS: The clinical records of mCRPC patients treated with AA at our tertiary care institute between July 2013 and December 2015 were reviewed. The treatment efficacy, toxicities, and its determinants were analyzed. RESULTS: A total of 59 mCRPC patients treated with AA were reviewed, of whom 37 were chemo-naive and 22 had received prior chemotherapy (postchemo). The median follow-up duration was 10.0/15.0 months for chemo-naïve/postchemotherapy patients. 43.2%/36.36% of chemo-naive/postchemo patients had visceral metastases. The median overall survival (OS) and progression-free survival (PFS) were 15/7.8 months and 10/5.3 months for chemo-naive/postchemo patients, respectively. Median time to best prostate-specific antigen response was 3.4 months. Abiraterone was relatively well tolerated with no grade 4 toxicity or treatment-related death. We found the presence of previous taxene use and baseline symptoms to be significantly determinant of OS with abiraterone. CONCLUSION: The present study reported the efficacy of abiraterone in both chemo-naïve and postchemo patients of mCRPC outside clinical trial setting. We found lower OS and PFS with abiraterone as compared to that reported in the clinical trial setting in both chemo-naïve and postchemo patients, and particularly in those patients with the visceral disease, and further clinical trial for abiraterone in this subgroup of patients is warranted.