AFP and cirrhosis of liver: When comparing, by meta-analysis, the baseline characteristics of the study groups (Table S1), we found no evidence to support a difference in terms of gender (p = 0.961), presence of underlying liver cirrhosis (p = 0.139), blood level of alpha-fetoprotein (p = 0.558), tumor size (p = 0.673), or in the proportion of patients with multinodular HCC (p = 0.812).