BACKGROUND/AIM: This study aimed to evaluate the therapeutic effect of enzalutamide (ENZ) or abiraterone acetate (ABI) on bone metastasis in castration-resistant prostate cancer (CRPC), using bone scan index (BSI). MATERIALS AND METHODS: Treatment outcomes for 31 patients who had undergone ENZ or ABI treatment were examined for CRPC with bone metastases. Cox proportional-hazards regression models were used to investigate the association between overall survival (OS) and clinical characteristics. RESULTS: Median OS after ENZ or ABI treatment was 29 months. Considering the flare phenomenon, BSI in 17 (55%) patients decreased following treatment. In multivariate analysis, low baseline BSI value and a decrease in BSI following treatment were associated with longer OS (hazard ratio [HR]=8.009; p=0.35 and HR=7.025; p=0.045*, respectively). CONCLUSION: Low BSI value before ENZ/ABI treatment and a decrease in BSI following ENZ or ABI treatment are independent predictors of longer OS. BSI could be useful for risk assessment of CRPC patients with bone metastases. Copyright
BACKGROUND/AIM: This study aimed to evaluate the therapeutic effect of enzalutamide (ENZ) or abiraterone acetate (ABI) on bone metastasis in castration-resistant prostate cancer (CRPC), using bone scan index (BSI). MATERIALS AND METHODS: Treatment outcomes for 31 patients who had undergone ENZ or ABI treatment were examined for CRPC with bone metastases. Cox proportional-hazards regression models were used to investigate the association between overall survival (OS) and clinical characteristics. RESULTS: Median OS after ENZ or ABI treatment was 29 months. Considering the flare phenomenon, BSI in 17 (55%) patients decreased following treatment. In multivariate analysis, low baseline BSI value and a decrease in BSI following treatment were associated with longer OS (hazard ratio [HR]=8.009; p=0.35 and HR=7.025; p=0.045*, respectively). CONCLUSION: Low BSI value before ENZ/ABI treatment and a decrease in BSI following ENZ or ABI treatment are independent predictors of longer OS. BSI could be useful for risk assessment of CRPC patients with bone metastases. Copyright