Main characteristics of the studies included in the meta-analysis.

† B−, B+, C−, and C+ represent negative HBs-Ag, positive HBs-Ag, negative anti-HCV Ab, and positive anti-HCV Ab, respectively. a, healthy control group; b, control group with chronic hepatitis; c, non-cancerous control group (healthy and chronic hepatitis B carriers). Age, mean or median age of HCC patients; Male, men with HCC; Se, sensitivity; Sp, specificity;NR = not report. Main characteristics of the studies included in the meta-analysis.