Fig. 3

High numbers of intraepithelial CD3+ and CD3+CD8-Foxp3- T cells are associated with longer overall survival and recurrence-free period. Kaplan-Meier curves showing overall survival (left) and the recurrence-free period (RFP; right) for VSCC patients with high (red) and low (blue) numbers of intraepithelial CD3⁺ (a) and CD3⁺CD8⁻Foxp3⁻ (b) and CD3⁺PD1⁺ (c) cells/mm². The patients were grouped based on the best cut-off value for each subset as determined by receiver operating characteristics (ROC) curve analysis. The most accurate T-cell subset values for either OS or RFP was used. Cut-off values were for CD3⁺ T cells 309.4 and 192.7 cells/mm² for OS and RFP, respectively, and for CD3⁺CD8⁻Foxp3⁻ T 82.58 and 61.82 cells/mm², respectively, and for CD3⁺PD1⁺ 37.67 (OS) and 99.96 (RFP) cells/mm² for CD3⁺PD1⁺ cells, respectively. Patients with a T-cell count < cut-off value were classified as low, the others as high. Statistical significance of the survival distribution was analyzed by log-rank testing and significant differences were indicated with an asterisk (*p < 0.05, **p < 0.01, *** p < 0.001 and **** p < 0.0001)