Serum Pre-Albumin Predicts the Clinical Outcome in Metastatic Castration-Resistant Prostate Cancer Patients Treated With Abiraterone

Objective To determine the prognostic utility of serum pre-albumin in metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone (AA). Patients and Methods 112 chemotherapy pretreated or chemotherapy-naive patients were scheduled for systemic treatment with AA. Serum pre-albumin levels were measured before and after 3 months of AA treatment. Univariate and multivariate analyses were performed to determine prognostic factors that were associated with PSA progression-free survival (PSA-PFS), radiographic PFS (rPFS) and overall survival (OS). The Harrell concordance index with variables only or combined pre-albumin data were used to evaluate the prognostic accuracy. Results The group of patients with baseline pre-albumin value ≥20mg/dL had a longer OS, PSA-PFS, rPFS than those with pre-albumin value <20mg/dL. Based on the values of pre-albumin before and after 3 months of AA treatment, we divided these patients into 4 groups: high-high, high-low, low-high and low-low group. High- high group showed a significantly better OS, PSA-PFS, rPFS than other 3 groups. In multivariate analysis, low pre-albumin level remained significant predictors of OS (HR, 13.2; P<0.001), rPFS (HR, 3.7; P=0.003) and PSA-PFS (HR, 8.7; P<0.001). The estimated c-index of the multivariate model for OS increased from 0.814 without pre-albumin to 0.845 when pre-albumin added. Conclusion Low pretreatment serum pre-albumin is a negative independent prognosticator of survival outcomes in mCRPC treated with AA and also increases the accuracy of established prognostic model. Serial pre-albumin evaluation might help clinicians guide clinical treatment of mCRPC patients.