Validation of the nomogram
The C-index of the nomogram in the training set and validation set is 0.778 (95% CI 0.758–0.798) and 0.765 (95% CI 0.743–0.787), respectively, indicating that the nomogram has good prediction accuracy. Calibration curve analysis showed that the survival rate predicted by the nomogram was in good agreement with the actual survival rate, indicating that the nomogram had better predictive performance (Fig. Calibration curves of the nomogram. (Decision curves of the nomogram. (