Nomogram construction and validation
Based on the independent prognostic analysis, nomograms were constructed to evaluate the predictive ability of the 1-year, 3-year and 5-year OS and CSS in elderly patients undergoing resection for LAGC (Figs. Nomogram for predicting the 1-, 3- and 5-year OS rates of elderly patients with LAGC. Higher scores indicate lower expected survival of patients. Abbreviations: Nomogram for the prediction of 1-, 3- and 5-year CSS rates of elderly patients with LAGC. Higher scores indicate lower expected survival of patients. Abbreviations: Scores of prognostic factors in the OS and CSS nomogramsFor nomogram validation, the discrimination and calibration of this novel model were assessed. In the training group, the c-indexes of the nomogram for the prediction of OS and CSS were 0.679 and 0.694, respectively. In the internal validation set, the c-indexes for OS and CSS prediction were 0.687 and 0.696, respectively. The c-indexes of the external validation cohort for OS and CSS all exceeded 0.7 (Table C-index of the two nomogram modelsIn addition, as shown in Fig. The calibration curves of the prognostic nomogram for 1-, 3-, and 5-year OS and CSS in the training set (