Fig. 3

Kaplan-Meier survival curve comparing tumor necrosis affecting postoperative survival of patients with small hepatocellular carcinoma (sHCC) stratified according to different tumor size, differentiation, serum AFP level and vascular invasion. a, e Tumor necrosis was associated with a decrease in overall survival (OS) of patients with tumor size ≤2.5 cm, and a decrease in recurrence-free survival (RFS) of patients with tumor size ≤2.5 cm as well as > 2.5 cm (P = 0.0200, 0.0020, 0.0240, respectively). b, f Tumor necrosis was associated with a decrease in OS and RFS of patients with AFP level ≤ 20 ng/ml and >  20 ng/ml (P = 0.0090, 0.0030, 0.0060, 0.0020, respectively). c, g Tumor necrosis was associated with a decrease in OS and RFS of patients with different tumor differentiation (P = 0.0210, < 0.0001, = 0.0110, < 0.0001, respectively). d, h Tumor necrosis was associated with a decrease in OS and RFS of patients with or without vascular invasion (P = 0.0380, 0.0040, 0.0210, 0.0030, respectively)