Fig. 2

Diagnostic values of PIVKA-II in AFP-negative HCC patients and patients with small HCC. a The AUROC of PIVKA- II to diagnose HCC patients with small HCC was 0.692 (95%CI 0.597–0.788, P < 0.001). The cut-off value was 32.10 mAU/ml, the sensitivity was 54.61%, specificity was 81.92%, +LR was 3.22 and -LR was 0.59. b The AUROC of PIVKA-II to diagnose AFP-negative HCC patients was 0.73 (95%CI 0.640–0.815, P < 0.001). The cut-off value was 32.09 mAU/ml, the sensitivity was 51.02%, the specificity was 84.47%, +LR was 3.29 and -LR was 0.5