Correlations of preoperative systematic immuno-inflammatory index and prognostic nutrition index with a prognosis of patients after radical gastric cancer surgery

This study aimed to explore the correlations of a preoperative systemic immune-inflammation index and prognostic nutritional index with the prognosis of patients after radical gastric cancer surgery.The receiver operating characteristic curve determined the optimal cut-off values of systemic immune-inflammation index, prognostic nutritional index, platelet-to-lymphocyte ratio, and neutrophil-to-lymphocyte ratio. Kaplan-Meier method and Cox proportional hazards model were used to evaluate the correlation between systemic immune-inflammation index, prognostic nutritional index, platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio, and patient prognosis. Finally, the receiver operating characteristic curve was adopted to evaluate the efficiency of systemic immune-inflammation index, prognostic nutritional index, and combination of systemic immune-inflammation index and prognostic nutritional index in predicting the prognosis of gastric cancer.We retrospectively analyzed 771 patients from June 2010 to June 2015. The results of Kaplan-Meier analysis showed that the 5-year overall survival was significantly higher in the low systemic immune-inflammation index group than in the high systemic immune-inflammation index group (67.9% vs 28.9%, P.001), and significantly lower in the low prognostic nutritional index group than in the high prognostic nutritional index group (46.2% vs 74.2%, P.001). Systemic immune-inflammation index and prognostic nutritional index were independent risk factors for the prognosis of patients with gastric cancer. The results of receiver operating characteristic curve analysis demonstrated that the area under the curve of combining systemic immune-inflammation index and prognostic nutritional index was the largest (area under the curve = 0.747, P.001), showing statistically significant differences between groups (P.05), so combining systemic immune-inflammation index and prognostic nutritional index has higher prediction efficiency.Systemic immune-inflammation index and prognostic nutritional index are independent risk factors for the prognosis of patients with gastric cancer. The decrease in systemic immune-inflammation index and the increase in prognostic nutritional index suggest a better prognosis, and the combination of systemic immune-inflammation index and prognostic nutritional index can improve the prediction efficiency.