Prognostic significance of metastatic lymph node ratio: the lymph node ratio could be a prognostic indicator for patients with gastric cancer

BACKGROUND: To demonstrate the prognostic significance and value of lymph node ratio (LNR) and evaluate the possibility of becoming a new indicator to enhance the current Union for International Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) tumor, lymph node, metastasis (TNM) staging system. METHODS: Our retrospective study included 221 patients who got gastric cancer and underwent curative gastrectomy between 2005 and 2012 at the Fourth Hospital Affiliated of China Medical University. The log-rank test was used to compare the clinicopathological variables. The Kaplan-Meier method and Cox proportional hazard regression model was used to perform the univariate analysis and multivariate statistical survival analysis. RESULTS: The patients with a better differentiated pathological type; an earlier stage of T staging, N staging, and TNM staging; and a lesser LNR would have a longer survival time according to the univariate analysis. As for the multivariate analysis, the Grade, T stage, N stage, and LNR had the statistical significance. Both in group 1 (the number of lymph nodes examined ≥ 15, namely LN ≥ 15) and group 2 (LN < 15), the LNR had statistical significance and the median survival time would decrease with the increase of the LNR. It was still statistically significant between group LNR1 and group LNR2 which were regrouped by the new cut-off value. CONCLUSION: The LNR could estimate the prognosis of patients with curative gastrectomy regardless of the number of lymph nodes examined. Thus LNR could become a new indicator to enhance the current TNM stage system.