Pretreatment serum albumin/globulin ratio as a prognostic biomarker in metastatic prostate cancer patients treated with maximal androgen blockade

The pretreatment serum albumin/globulin ratio (AGR) has been used as a prognostic biomarker for various cancer types. However, the prognostic value of the AGR for prostate cancer, especially for metastatic prostate cancer (mPCa) after maximal androgen blockade (MAB), remains unclear. The aim of this study was to evaluate the prognostic value of the pretreatment serum AGR for mPCa treated with MAB. This retrospective study included 214 mPCa patients receiving MAB from October 2007 to March 2017. The correlation of the AGR with survival was estimated using Kaplan–Meier analysis and Cox proportional hazards models. The cutoff value of the AGR was 1.45 according to the receiver operating characteristic curve. Kaplan–Meier analysis demonstrated that patients with a low AGR (<1.45) had poor outcomes in terms of progression-free survival (PFS) and cancer-specific survival (CSS). Multivariate Cox analyses showed that the AGR was an independent predictor of PFS (hazard ratio [HR] = 0.642; 95% confidence interval [CI]: 0.430–0.957; P = 0.030) and CSS (HR = 0.412; 95% CI: 0.259–0.654; P < 0.001). Furthermore, in a subset of 79 patients with normal serum albumin levels (≥40.0 g l(−1)), the serum AGR remained an independent predictor of CSS (P = 0.009). The pretreatment AGR was an independent prognostic biomarker for PFS and CSS in patients with mPCa receiving MAB. In addition, the AGR remained effective for the prediction of CSS in patients with normal albumin levels (≥40 g l(−1)). However, further prospective studies are needed to confirm our conclusions.