Evaluation of the OS nomogram
The C-indexes of the OS nomogram were 0.737 and 0.735, in the training and validation cohorts, respectively, compared with 0.582 and 0.573 for AJCC staging. Our model demonstrates superior discriminatory performance and prognostic ability compared to AJCC staging, as evidenced by its C-index values exceeding 0.7 and surpassing those of AJCC staging.The AUC values for OS at 3, 5, and 8 years were 0.767, 0.789, and 0.789, respectively, in the training cohort, and 0.757, 0.773, and 0.792 in the validation cohort. The AUC was > 0.7 for the prediction of OS at 3, 5, and 8 years in both the training and validation cohorts (Receiver operating characteristic curves. ROC curve analyses to evaluate the performance of the new model compared to the traditional AJCC model. The area under the curve (AUC) metric was used to predict the overall survival probability with 3-, 5-, and 8-years OS probability in the training and validation cohorts. The results of the training cohort represent in For the 3-, 5-, and 8-year OS probabilities, the NRI values were 68.08% (95% confidence interval [CI] = 0.559–0.867), 77.56% (95% CI = 0.677–0.945), and 79.34% (95% CI = 0.699–0.960), respectively, in the training cohort, and 55.72% (95% CI = 0.226–0.829), 63.71% (95% CI = 0.363–0.876), and 78.23% (95% CI = 0.561–0.964) in the validation cohort. The corresponding IDI values were 15.48%, 20.23%, 23.66%, 13.65%, 20.52%, and 23.73% (p = 0.001), respectively. When compared with the AJCC staging system, the new model performed much better in every circumstance in which the IDI and NRI values were higher than zero. These results indicating that the nomogram predicted prognosis with greater accuracy than the AJCC staging.The calibration plot was used to test whether the model effectively differentiated between actual and expected values. The calibration curves of the nomogram showed high consistency between the predicted and observed survival probabilities in both the training and validation cohorts. In summary, the calibration plot of the OS nomogram demonstrated that the expected 3-, 5-, and 8-year survival probabilities for the training and validation cohorts closely matched the survival probabilities calculated using the actual data (Calibration curves. Calibration curves for 3-, 5-, and 8-year OS depict the calibration of each model in terms of agreement between the predicted probabilities and observed outcomes of the training cohort Ultimately, A decision-curve analysis (DCA) was conducted to assess the clinical validity of the new model, and satisfactory results were obtained for curves calculated at 3, 5, and 8 years in the training and validation cohorts (Decision curve analysis curves. Decision curve analysis of the nomogram for prediction of 3-, 5-, and 8-years overall survival probability with CVC patients. 