Validation of the Prognostic Value of Preoperative Albumin-to-Alkaline Phosphatase Ratio in Patients with Surgically Treated Non-Metastatic Renal Cell Carcinoma

PURPOSE: Several studies have revealed that albumin-to-alkaline phosphatase ratio (AAPR) was correlated to the survival of several cancers. To explore the impact of AAPR on the survival of non-metastatic renal cell carcinoma (RCC) patients following nephrectomy, the present study was conducted. PATIENTS AND METHODS: A total of 648 patients were enrolled in the present study. The cut-off value of AAPR was determined based on the receiver-operating characteristic (ROC) analysis. Univariate and multivariate analyses were applied to identify prognostic factors. The discrimination and calibration of models for survival outcomes were evaluated based on the concordance index (C-index), ROC analysis and calibration curve. RESULTS: The low AAPR (≤0.5) was associated with older age (P<0.001), higher T stage (P=0.002), larger tumor size (P=0.014) and tumor necrosis (P=0.003). A high AAPR was significantly correlated to better OS (hazard ratio, HR=0.61; P=0.038) and CSS (HR=0.52; P=0.013) based on multivariate analysis. Integrating AAPR with UISS or SSIGN, the C-indexes of nomogram for OS (UISS: 0.790 vs 0.765; SSIGN: 0.861 vs 0.850) and CSS (UISS: 0.832 vs 0.805; SSIGN: 0.905 vs 0.896) increased. Moreover, the nomogram for OS and CSS was established based on the multivariate analysis. The C-indexes of nomogram for OS and CSS were 0.834 (95% CI 0.794–0.874) and 0.867 (95% CI 0.830–0.904), respectively. CONCLUSION: In conclusion, the high preoperative AAPR was a favorable prognostic factor for surgically treated non-metastatic RCC patients. AAPR also could improve the predictive value of well-established models. The nomogram that incorporates AAPR had a good performance. More prospective studies with a large scale are essential to validate our findings.