Prognostic significance of preoperative gamma-glutamyltransferase to lymphocyte ratio index in nonfunctional pancreatic neuroendocrine tumors after curative resection

Various inflammation-based prognostic scores have been associated with reduced survival in patients with nonfunctional pancreatic neuroendocrine tumor (NF-PNET). However, few studies have illuminated the relationship between the preoperative gamma-glutamyltransferase (GGT) to lymphocyte ratio index (GLRI) and the prognosis of NF-PNET. A retrospective review of 125 NF-PNET patients following curative resection was conducted. The cut-off values for the inflammation-based prognostic scores, including GLRI, were selected using receiver operating characteristic curve analysis. Univariate, multivariate and Kaplan-Meier analyses were used to calculate overall survival (OS) and disease-free survival (DFS). The optimal cut-off value for GLRI was 10.3. Multivariate analysis showed that GLRI was an independent predictor of OS (P = 0.001) and DFS (P = 0.007) for NF-PNET. Kaplan-Meier analysis also showed that preoperative GLRI had significant prognostic value in various subgroups of patients with NF-PNET. The discriminatory capability of GLRI was superior to that of other inflammation-based scores in OS prediction. Furthermore, the predictive range was expanded by incorporating GLRI into the conventional stratification systems, including AJCC staging and WHO classification. These results indicated that preoperative GLRI was an independent predictor for NF-PNET patients undergoing curative resection. The incorporation of GLRI into the existing conventional stratification systems resulted in improved predictive accuracy.