Prognostic Significance Of Lymph Node Metastasis Ratio In Patients With Gastric Cancer

Background: Gastric cancer is one of the common gastrointestinal tumors with high morbidity and mortality rates,which seriously threatens the life and health of patients.The Union for International Cancer Control(UICC)/ the American Joint Committee on Cancer(AJCC)updated the eighth edition of the gastric cancer TNM staging system in 2017.In clinical practice,there is staging bias phenomenon appears when evaluating patients with this system.This research studied the lymph nodes ratio(LNR)of gastric cancer patients,on its influence to the prognostics,and further evaluated whether it could be a new indicator to perfect the TNM staging system as a supplementMethods: Retrospective study included 211 patients treated with radical gastrectomy for gastric cancer between January 2010 and December 2015.All the clinicopathological data were labeled and input to computers to establish a database.The SPSS22.0 software was used for statistical analysis.The Kaplan-Meier method is used to compare the differences among clinicopathological variables.Statistical significant differences among survival curves were examined by logarithmic rank test.Monofactor analysis of pathological data.For the variables with statistical significance in monofactor analysis,the method of gradual introduction of variables into the Cox proportional risk regression model is introduced,in order to determine the independent factors affecting the prognosis of gastric cancer.Results: In monofactor analysis,the factors of cancer differentiation(P <0.001),T stage(P<0.001),N stage(P <0.001),TNM Phase(P <0.001),LNR(P <0.001)were statistically significant.All of the nine clinicopathological variables were included in multivariate analysis by Cox proportional risk model.Multivariate analysis showed that the tumor differentiation,T stage,N stage and LNR are still of statistical significance.In ‘enough group’,a total of 122 patients were found with ≥16lymph nodes,with LNR0(LNR =0)17 cases(13.8%),LNR1(0<LNR≤0.13)23 cases(18.9%),LNR2(0<LNR≤0.38)39 cases(32.0%),and LNR3(LNR >0.38)43 cases(35.2%).The monofector analysis provided results of statistical significance(P<0.001).There were 89 patients in ‘non-enough group’ with <16 lymph nodes,with LNR0(LNR =0)23 cases(25.9%),LNR1(0<LNR≤0.13)10 cases(11.2%),LNR2(0<LNR≤0.38)23 cases(25.9%),and LNR3(LNR >0.38)33 cases(37.0%).In monofactor analysis we still obtained statistically significant results(P<0.001).Conclusion: Tumor differentiation,T stage,N stage and LNR are independent risk factors for gastric cancer prognosis.LNR can be used as an assistant index in the TNM staging system to evaluate the prognosis of gastric cancer,especially when the number of lymph nodes <16.