Table 1.
Characteristics and disease-free survival rate in 284 gastric cancer patient undergoing potentially curative surgery from 2000 to 2014 at Second University of Naples.
Table 2.
Table 3.
Table 4.
Prognostic performance between the current and new nodal and TNM stages.
Table 5.
Prognostic performance between the current and new nodal and TNM stages.
Bootstrap analysis.
Table 6.
Patient distribution according to the TNM 7th edition and the new staging system.
Fig 1.
Disease-free survival rates for each staging system.
(A) Current N stage. Shown are P values for pairwise comparisons of DFS curves in N0 vs. N1, N1 vs. N2, N2 vs. N3a, and N3a vs. N3b. (B) New N stage. Shown are P values for pairwise comparisons of DFS curves in new N0 vs. N1, N1 vs. N2, and N2 vs. N3. (C) Current TNM stage. Shown are P values for pairwise comparisons of DFS curves in different substages. (D) New TNM stage. Shown are P values for pairwise comparisons of DFS curves in different substages. Note to figures 1C and 1D: The iterations required to achieve significant DFS rates among different substages were eleven in the current TNM staging system (IA vs. IB, P = 0.207; IA vs. IIA, P = 0.007; IB vs. IIA, P = 0.060; IB vs. IIB, P < 0.001; IIA vs. IIB, P = 0.154; IIA vs. IIIA, P = 0.002; IIB vs. IIIA, P = 0.069; IIB vs. IIIB, P < 0.001; IIIA vs. IIIB, P = 0.096; IIIA vs. IIIC, P = 0.044; IIIB vs. IIIC, P = 0.433) and eight in the new TNM staging system (IA vs. IB, P = 0.388; IA vs. IIA, P = 0.003; IB vs. IIA, P = 0.006; IIA vs. IIB, P = 0.653; IIA vs. IIIA, P = 0.012; IIB vs. IIIA, P = 0.015; IIIA vs. IIIB, P = 0.046; IIIb vs. IIIC, P = 0.241).
Fig 2.
Disease-free survival rates for new N stages.
(A) DFS rates among each combination of anatomical location-based lymph node groups [LC: lesser curvature; GC: greater curvature; EP: extraperigastric nodes]. (B) DFS rates for each new N stage at current N1 stage. Shown are P values for pairwise comparison of DFS curves in new N1 and N2. (C) DFS rates for each new N stage at current N2 stage. Shown are P values for pairwise comparisons of DFS curves in new N1 and N2, and N2 and N3. All curves P < 0.001. (D) DFS rates for each new N stage at current N3 stage. Shown are P values for pairwise comparison of DFS curves in new N2 and N3.
Table 7.
Multivariate analysis related to disease-free survival in 284 gastric cancer patients undergoing potentially curative surgery.
Cox's proportional-hazards model.
Fig 3.
Accuracy of the competing staging systems to predict disease-free survival rate.
(A) Results from bootstrap analysis (1,000 samples). The mean differences in BIC and Harrell C-index with 95% confidence intervals were based on multivariable logistic regression including variables grouped in the best model selected by Cox's analysis. The mean differences in the Area Under the Curve (AUC) for TNM stage and AUC for N stage with 95% confidence intervals were calculated by using the time-dependent receiver-operating-characteristic (ROC) analysis for censored survival data. By these procedures, 95% CIs were computed for differences in the four indices indicating significantly different predictive ability of two staging systems if the zero value was not included. (B) Areas under the ROC curves computed by the time-dependent analysis for censored survival data based on different staging systems according to TNM 7th edition and the new TNM model. Mean AUC values and their 95% CIs were calculated at several time points of follow-up and for each competing system. Error bars represent 95% bootstrap confidence intervals. (C) Analysis of the predictive accuracy of the two competing staging systems through the 5th year of follow-up, computed by the time-dependent ROC analysis for censored survival data.