ROC curve analysis of the NLR, IL-6 level and the NLR + IL-6 level in CRC patients. ROC curve analysis of the NLR and IL-6 level for OS (A) and DFS (B). ROC curve analysis of the NLR + IL-6 level for OS (C) and DFS (D). The prognostic scores of the NLR were assigned to scores of 1 (≥2.99) or scores of 0 (<2.99). The prognostic scores of IL-6 were assigned to scores of 1 (≥213.83 pg/mL) or scores of 0 (<213.83 pg/mL). The prognostic scores of the combination of the NLR and IL-6 level were scores of 2 (NLR ≥2.99 and ≥213.83 pg/mL), 1 (NLR ≥2.99 or ≥213.83 pg/mL), or 0 (neither NLR ≥2.43 nor ≥213.83 pg/mL). NLR, neutrophil to lymphocyte ratio; IL-6, interleukin-6; CRC, colorectal cancer; OS, overall survival; DFS, disease-free survival.