Fig. 2

Validation of the 81 CSC gene expression signatures in the four independent HNSCC cohorts. Each cohort was stratified into CSC-HR and CSC-LR subgroups, on the basis of the 81 CSC gene expression signatures. The predicted outcomes in the four cohorts were assessed using Kaplan–Meier plots and ROC curves. a, c, e The 5-year OS rates of each subgroup were determined in the Leipzig (n = 270), FHCRC (n = 97), and MDACC (n = 109) cohorts (p = 0.06, < 0.0001, and 0.02, respectively). b, d, f The ROC curves show the sensitivity and specificity of the CSC gene expression signatures in predicting 1-year, 3-year, and 5-year patient OS rates in the Leipzig, FHCRC, and MDACC cohorts (AUC = 0.541, 0.671, and 0.876 for the 5-year OS, respectively). g The 5-year RFS rates of each subgroup was determined in the Greece cohort (n = 109; p = 0.009). h ROC curves show the sensitivity and specificity of the CSC gene expression signatures in predicting 1-year, 3-year, and 5-year patient RFS rates in the Greece cohorts (AUC = 0.538 for the 5-year RFS). *p < 0.05