Background: As a promising biomarker of hepatocellular carcinoma (HCC), protein induced by vitamin K absence or antagonist-II (PIVKA-II) has been studied extensively. However, its diagnostic capability varies across HCC studies. This study aimed to compare the performance of PIVKA-II with alpha-fetoprotein (AFP) in the diagnosis of HCC.

Data sources: A systematic literature search was conducted to identify the studies from MEDLINE, Embase and Cochrane Library Databases, which were published up to December 20, 2017 to compare the diagnostic capability of PIVKA-II and AFP for HCC. The data were pooled using random effects model. Pooled sensitivity and specificity were calculated. Summary receiver operating characteristic curve (ROC) was employed to evaluate the diagnostic accuracy of each marker.

Results: Thirty-one studies were included. The pooled sensitivity (95% CI) of PIVKA-II and AFP was 0.66 (0.65-0.68) and 0.66 (0.65-0.67), respectively in diagnosis of HCC; and the corresponding pooled specificity (95% CI) was 0.89 (0.88-0.90) and 0.84 (0.83-0.85), respectively. The area under the ROC curve (AUC) of PIVKA-II and AFP was 0.856 (0.817-0.895) and 0.770 (0.728-0.811), respectively. Subgroup analysis showed that PIVKA-II was superior to AFP in terms of the AUC for both small HCC (< 3 cm) [0.863 (0.825-0.901) vs 0.717 (0.658-0.776)] and large HCC (≥ 3 cm) [0.854 (0.811-0.897) vs 0.729 (0.682-0.776)]; for American [0.926 (0.897-0.955) vs 0.698 (0.594-0.662)], European [0.772 (0.743-0.801) vs 0.628 (0.594-0.662)], Asian [0.838 (0.812-0.864) vs 0.785 (0.764-0.806)] and African [0.812 (0.794-0.840) vs 0.721 (0.675-0.767)] HCC patients; and for HBV-related [0.909 (0.866-0.951) vs 0.714 (0.673-0.755)] and mixed-etiology [0.847 (0.821-0.873) vs 0.794 (0.772-0.816)] HCC.

Conclusion: This meta-analysis indicates that PIVKA-II is better than AFP in terms of the accuracy for diagnosing HCC, regardless of tumor size, patient ethnic group, or HCC etiology.