Decreased albumin-to-alkaline phosphatase ratio predicted poor survival of resectable gastric cancer patients.

Background The albumin-to-alkaline phosphatase ratio (AAPR) is an innovative prognostic index for various cancer patients, the clinical significance of the AAPR in patients with GC is unknown. Methods We retrospectively reviewed 227 resectable GC patients in our center. The Kaplan-Meier method and the Cox proportional hazards model were used to analyze the disease-free survival (DFS) and overall survival (OS). The Likelihood Ratio Test (LRT) and Akaike information criterion (AIC) were used to compare the prognostic abilities of the TNM and AAPR-TNM staging systems in DFS and OS prediction. Results The AAPR was significantly decreased in GC patients, and the optimal cut-off value for resectable and benign gastric disease was 0.437 as determined by the receiver operating characteristic (ROC) curve. The correlation analysis revealed that decreased AAPR in GC was associated with T stage (P=0.004) and TNM stage (P=0.013). Decreased preoperative AAPR correlated with both unfavorable disease-free survival (DFS) and overall survival (OS). Cox regression analysis showed that the TNM stage (DFS: P=0.001, OS: P=0.002) and differential levels of AAPR (DFS: P<0.001, OS: P<0.001) were independent risk factors of DFS and OS. ROC analysis showed that the AAPR-TNM system was more superior than the TNM staging system for DFS (z=1.91, P=0.028) and OS (z=1.937, P=0.026) prediction. The likelihood ratio test (LRT) analysis indicated that the AAPR-TNM system had a significantly larger χ2 for both DFS (35.58 vs. 34.51, P<0.001) and OS (32.92 vs. 30.07, P<0.001), and a lower Akaike information criterion (AIC) value both for DFS (1,032 vs. 1,065, P<0.001) and OS (869 vs. 898, P<0.001) compared to the TNM system. Conclusions The AAPR level significantly decreased in patients with GC, and impacted the prognosis of patients.