Fig. 7

Construction and validation of nomogram. Single-factor and multi-factor Cox regression analyses were performed in the training and validation sets, respectively. In univariate analysis, TNM staging (P < 0.001) and risk score (P < 0.001) were significantly associated with OS in TCGA training cohort (a). TNM stage (P < 0.001), risk score (P < 0.001) and age (P = 0.002) were identified as an independent prognostic factor strongly associated with OS (b). In the validation cohort, single-factor Cox analysis showed that the risk score (P < 0.001), TNM stage (P < 0.001), age (P = 0.015), and OS were highly correlated (c). TNM stage (P < 0.001), risk score (P < 0.001), and age (P = 0.003) remained significantly associated with OS in single-factor Cox analysis (d). A nomogram was constructed that included risk scores and clinical attributes. The risk score, age, sex, and TNM stage were summed to calculate the total score (e). The calibration curves for predicting 1-, 3-, and 5-year OS showed that survival predicted by the nomogram was closely related to the actual survival outcome (f–h). The AUC values at 1, 3, and 5 years were 0.797, 0.826, and 0.808, respectively, which were higher than those for clinical characteristics such as risk score and TNM staging (i-k)