Objective:To investigate the the correlation between lymphatic vascular invasion (LVI) and prognosis in T3/T4 gastric cancer after D2 resection, and establish an optimal classification of staging system. Methods: From Jan 2000 to Sep 2010, a total of 1, 283 T3/T4 gastric cancer patients undergoing D2 resection were enrolled. Univariate and multivariate analysis were used to investigate the prognostic value of gastric cancer patients. Homogeneity, discriminatory ability, and monotonicity of gradients of hypothetical N stage and UICC N stage were compared using linear trendχ2, likelihood ratioχ2 statistics, and Akaike information criterion (AIC) calculations.Results:Multivariate analysis identified LVI was an independent prognostic factor. The 3.5-year overall survival were worse in patients with LVI than those without LVI (P<0.001). LVI was corporated into N3b stage performed the optimum prognostic stratification, together with better homogeneity, discriminatory ability and monotonicity of gradients. Conclusion:LVI is an independent prognostic factor for T3/T4 gastric cancer atfer D2 resection, and may be considered to be incorporated into the UICC N3b stage.

Objective:This study examined the prognosis of the “node-negative with eLNs≤15” designation and the additional value of incorporating it into the pN1 designation in the seventh edition N classification.Methods: From Jan 2000 to Sep 2010, a total of 1,258 gastric cancer patients undergoing radical gastric resection were enrolled. We incorporated node-negative patients with eLNs≤15 into pN1 and compared this designation with the 7th edition UICC N stage for 3.5- year overall survival by univariate and multivariate analysis. Homogeneity, discriminatory ability, and monotonicity of gradients in hypothetical N stage and UICC N stage were compared using linear trendχ2, likelihood ratioχ2 statistics, and Akaike information criterion (AIC) calculations.Results:Node-negative patients with eLNs≤15 had worse survival compared with those with eLNs >15. The hypothetical N stage had higher linear trend and likelihood ratioχ2 scores and smaller AIC values compared with those for the 7th edition N stage, which represented the optimum prognostic stratification.Conclusion:Node-negative patients with eLNs≤15 can be considered to be incorporated into the pN1 stage in the 7th edition of th e TNM classiifcation.