3.5. Validation of Nomogram in Training Cohort and Validation Cohort
The discrimination of the nomogram was assessed by time-dependent ROC analysis in both the training cohort and validation cohort (Figures The discrimination of this nomogram was further assessed by the bootstrap validation with 1000 resamplings. The bootstrap-corrected Cindex of the nomogram was 0.72 (95% CI: (0.66, 0.78); 3-year-CSS) and 0.75 (95% CI: (0.70, 0.81); 5-year-CSS) in training cohort and 0.69 (95% CI: (0.60, 0.78); 3-year-CSS) and 0.71 (95% CI: (0.62, 0.80); 5-year-CSS) in validation cohort. The bootstrapped calibration plots for the prediction of 3-year and 5-year CSS in training cohort and validation cohort are shown in 