Evaluation of Blood-based Biomarkers for Prediction of Response in Carboplatin-treated Metastatic Castration-resistant Prostate Cancer Patients.

BACKGROUND/AIM Carboplatin-containing treatment regimens demonstrate moderate efficacy in metastatic castration-resistant prostate cancer (mCRPC). In this study, we retrospectively analyzed the efficacy of carboplatin in relation to blood-based parameters. PATIENTS AND METHODS A retrospective chart review was performed for 20 patients with mCRPC who received carboplatin in a single center. RESULTS Median overall survival was 3.8 months (95%CI=1.5-7.1), median progression-free survival was 1.7 months. We observed two partial remissions (PR, 10%), four stable diseases (SD, 20%) and 14 disease progressions (PD, 70%), resulting in a clinical benefit rate of 30%. A doubling of NSE (neurone specific enolase) values was associated with a 19% absolute higher response rate (95%CI=14-23, p=0.027). All other laboratory parameters failed as predictive markers of response to carboplatin. In univariate Cox regression analysis, only NSE was significantly associated with impaired PFS (HR=0.7, 95%CI=0.56-0.96, p=0.030). CONCLUSION Carboplatin showed moderate efficacy against mCRPC in this unselected population of patients and NSE levels may help to predict the success of this treatment.