Accurate Risk Stratification of Patients with Node-Positive Gastric Cancer by Lymph Node Ratio

Background We aimed to clarify the utility of lymph node ratio (LNR) for assessing the prognosis of patients with node-positive gastric cancer after curative gastrectomy. Methods We retrospectively analyzed data of 973 patients with node-positive gastric cancer who had undergone curative gastrectomy at nine institutions from 2010 to 2014. Survival analysis was performed by comparing LNR low and high groups according to the optimal cutoff value of LNR, which was determined using receiver operating characteristic curve analysis. Results LNR high was significantly associated with shorter disease-free survival and was an independent predictor of recurrence in all patients. Moreover, we obtained the similar results from analysis of each N stage. The prevalence of lymph node and peritoneal recurrence appeared to be higher in the LNR high group. Correlation analysis showed that LNR was negatively correlated with the number of retrieved nodes within every N stage; however, disease-free survival did not differ significantly between LNR low and high groups of each N stage with 16–30, 31–40, or >40 retrieved nodes. Conclusions LNR is a strong prognostic factor and predictor of recurrence in patients with node-positive gastric cancer who have undergone curative gastrectomy. The combination of LNR and N staging permits more accurate prognostic stratification of patients with gastric cancer and may contribute to developing novel prognostic models.