Preliminary efficacy and tolerability of chemohormonal therapy in metastatic hormone‐naïve prostate cancer: The first real‐life experience in Asia

INTRODUCTION: A substantial survival benefit with chemohormonal therapy has been proven by the CHAARTED and STAMPEDE studies, and this clinical approach has emerged as the standard of care for patients with metastatic hormone-naive prostate cancer (mHSPC). However, because its clinical efficacy and tolerability in Asian patients remains uncertain, this study aims to evaluate preliminary results of its use in Hong Kong. METHODS: The clinical records of mHSPC patients treated with chemohormonal therapy from all six public oncology centers in Hong Kong between January 2015 and July 2016 were reviewed. Time to castration-resistant prostate cancer (CRPC), treatment-related complications, prostate-specific antigen (PSA) response and the time to PSA nadir were assessed. RESULTS: A total of 32 patients (median age, 66 years) were treated with chemohormonal therapy in the review period. After median follow-up time of 11.4 months, the median time to CRPC and time to PSA nadir were 19.5 months and 7 months, respectively. PSA response (>50% drop in PSA level from baseline) was achieved in all patients and the median maximal PSA response was 99.6%. The rates of grade 3 or 4 febrile neutropenia, neutropenia and anemia were 12.5%, 40.6% and 3.1%, respectively. CONCLUSION: Early efficacy with chemohormonal therapy in Asian mHSPC patients was comparable to the pivotal study and biochemical response is promising. The high frequency of hematologic toxicities in Asian patients highlights the importance of proper patient selection and pre-emptive use of granulocyte colony-stimulating factor.