Abstract: Objective To investigate the value of the ratio of neutrophil to lymphocyte (NLR), monocyte to lymphocyte (MLR), platelet to lymphocyte (PLR), and systemic immune inflammatory index (SⅡ) in the diagnosis of lymph node metastasis of gastric cancer. Methods A total of 98 patients, which were screened for gastric cancer in our hospital from January 2017 to December 2019, were divided into gastric cancer group(61 cases) and gastric benign disease group(37 cases) by pathological diagnosis. According to the lymph node metastasis, gastric cancer group was further divided into lymph node metastasis group (35 cases) and non lymph node metastasis group (26 cases). NLR, MLR, PLR and SⅡ were calculated according to the results of preoperative blood routine test, and the efficiency of each index in the diagnosis of lymph node metastasis was analyzed. Results Among 61 cases of gastric cancer, 35 cases had lymph node metastasis, the metastasis rate was 57.38%. The levels of NLR, MLR, PLR and SⅡ in lymph node metastasis group were significantly higher than those in non lymph node metastasis group and gastric benign disease group(P<0.01). The area under ROC curve of NLR, MLR, PLR and SⅡ was 0.761, 0.708, 0.686 and 0.781, respectively. The critical values of NLR, MLR, PLR and SⅡ were 3.23, 0.29, 197.7 and 574.47, respectively. NLR, MLR, PLR and SⅡ were correlated with tumor differentiation, invasion, diameter and stage. Patients with lower differentiation, deeper invasion, larger diameter and higher stage had higher values of NLR, MLR, PLR and SⅡ (P<0.05). There was no significant difference in NLR, MLR, PLR and SⅡ (P>0.05) with tumor location. Conclusion NLR, MLR, PLR and SⅡ are related to the differentiation, invasion, diameter and stage of gastric cancer, which could be helpful for the diagnosis of lymph node metastasis of gastric cancer, and provide a reference for the choice of surgical methods and the scope of lymph node dissection.

Key words: Gastric cancer, Lymph node metastasis, Neutrophil to lymphocyte ratio, Monocyte to lymphocyte ratio, Platelet to lymphocyte ratio, Systemic immune inflammation index