Prognostic Value of the Lymph Node Ratio in Stage III Gastric Cancer Patients Undergoing Radical Resection

Objective: The aim of this study was to investigate the prognostic value of metastatic lymph node ratio (LNR) in patients having radical resection for stage III gastric cancer. Methods: A total of 365 patients with stage III gastric cancer who underwent radical resection between 2002 and 2008 at Tianjin Medical University Cancer Institute and Hospital were analyzed. The cut-point survival analysis was adopted to determine the appropriate cutoffs for LNR. Kaplan-Meier survival curves and log-rank tests were used for the survival analysis. Results: By cut-point survival analysis, the LNR staging system was generated using 0.25 and 0.50 as the cutoff values. Pearson's correlation test revealed that the LNR was related with metastatic lymph nodes but not related with total harvested lymph nodes. Cox regression analysis showed that depth of invasion and LNR were the independent predictors of survival (p<0.05). There was a significant difference in survival between each pN stages classified by the LNR staging, however no significant difference was found in survival rate between each LNR stages classified by the pN staging. Conclusions: The LNR is an independent prognostic factor for survival in stage III gastric cancer and is superior to the pN category in TNM staging. It may be considered as a prognostic variable in future staging system.