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.

Objective:We investigated the prognostic value of the lymph node ratio (LNR), determined different cut-points in cohorts with examined lymph nodes (eLNs)≤15 or eLNs >15, and compared hypothetical pNr with 7th edition UICC pN stage.Methods:A total of 1,772 gastric cancer patients undergoing D2 resection were enrolled. All patients were divided into two sub-cohorts according to eLNs≤15 or eLNs >15. The optimal LNR cut-point was calculated using decision tree method. Homogeneity, discriminatory ability, and monotonicity of gradients of the pNr and UICC pNstages were compared using linear trendχ2, likelihood ratioχ2 statistics, and Akaike information criterion (AIC) calculations.Results:hTe optimal cut-points were 0, 20, 35, 65 in eLNs >15 cohort and 0, 35, 70 in eLNs≤15 cohort. pNr stage was an independent factor for gastric cancer prognosis. hTe pNr stage had higher linear trend and likelihood ratioχ2 scores and lower AIC values compared with those for UICC pN stage.Conclusion:The LNR cut-point should be different according to the numbers of eLNs. pNr can predict survival more accurately than UICC pN stage in both the≤15 and the >15 eLNs cohorts.

Objective:To develop an easy applicable novel nodal grading system to improve the standardization of nodal classification in patients with limited lymphadenectomy. Methods: We formulated a new approach of nodal classification to classify this category of patients. Log-rank test was used for univariate analysis and Cox proportional hazards model was used for univariate and multivariate analysis. We used linear trendχ2 tests, likelihood ratioχ2 test and Akaike information criterion (AIC) value to assess the homogeneity, discriminatory ability and monotonicity of gradients of the two nodal staging systems.Results:Statistical analysis supported that both the hypothesized N’ stage and hypothesized TN’M stage outperforms the present AJCC/UICC staging system.Conclusion:We developed an easy applicable and reproducible novel nodal grading system that has a greater predicting value than the current AJCC/UICC staging system to classify gastric cancer patients with limited lymphadenectomy.