γ-glutamyl transferase-to-platelet ratio based nomogram predicting overall survival of gallbladder carcinoma

BACKGROUND: Gallbladder carcinoma (GBC) carries a poor prognosis and requires a prediction method. Gamma-glutamyl transferase–to–platelet ratio (GPR) is a recently reported cancer prognostic factor. Although the mechanism for the relationship between GPR and poor cancer prognosis remains unclear, studies have demonstrated the clinical effect of both gamma-glutamyl transferase and platelet count on GBC and related gallbladder diseases. AIM: To assess the prognostic value of GPR and to design a prognostic nomogram for GBC. METHODS: The analysis involved 130 GBC patients who underwent surgery at Peking Union Medical College Hospital from December 2003 to April 2017. The patients were stratified into a high- or low-GPR group. The predictive ability of GPR was evaluated by Kaplan–Meier analysis and a Cox regression model. We developed a nomogram based on GPR, which we verified using calibration curves. The nomogram and other prognosis prediction models were compared using time-dependent receiver operating characteristic curves and the concordance index. RESULTS: Patients in the high-GPR group had a higher risk of jaundice, were older, and had higher carbohydrate antigen 19-9 levels and worse postoperative outcomes. Univariate analysis revealed that GPR, age, body mass index, tumor–node–metastasis (TNM) stage, jaundice, cancer cell differentiation degree, and carcinoembryonic antigen and carbohydrate antigen 19-9 levels were related to overall survival (OS). Multivariate analysis confirmed that GPR, body mass index, age, and TNM stage were independent predictors of poor OS. Calibration curves were highly consistent with actual observations. Comparisons of time-dependent receiver operating characteristic curves and the concordance index showed advantages for the nomogram over TNM staging. CONCLUSION: GPR is an independent predictor of GBC prognosis, and nomogram-integrated GPR is a promising predictive model for OS in GBC.