Pretreatment serum albumin-to-alkaline phosphatase ratio is an independent prognosticator of survival in patients with metastatic gastric cancer.

Background: Previous studies have suggested that a low albumin-to-alkaline phosphatase ratio (AAPR) is associated with a lower survival rate in patients with various malignancies. However, the relationship between pretreatment AAPR and the prognosis of patients with gastric cancer (GC) remains unclear.

Aim: To investigate the prognostic value of AAPR in distant metastatic GC.

Methods: A total of 191 patients with distant metastatic cancer from a single institute were enrolled in this study. Pretreatment clinical data, including serum albumin and alkaline phosphatase levels, were collected. A chi-square test or Fisher's exact test was applied to evaluate the correlations between AAPR and various clinical parameters in GC patients. The Kaplan-Meier method and Cox proportional hazards regression model were used to evaluate the prognostic efficacy of AAPR in metastatic GC patients. A two-sided value lower than 0.05 was considered statistically significant.

Results: A receiver operating characteristic curve indicated that 0.48 was the optimal threshold value for AAPR. AAPR ≤ 0.48 was significantly associated with bone ( < 0.05) and liver metastasis ( < 0.05). Patients with high levels of AAPR had better survival in terms of overall survival (OS) and progression-free survival (PFS), regardless of the presence of liver/bone metastasis. Pretreatment AAPR was found to be a favorable predictor of OS and PFS based on a multivariate cox regression model. AAPR-M system, constructed based on AAPR and number of metastatic sites, showed superior predictive ability relative to the number of metastatic sites for predicting survival.

Conclusion: Pretreatment AAPR may serve as an independent prognostic factor for predicting PFS and OS in patients with metastatic GC. Furthermore, AAPR may assist clinicians with individualizing treatment.