Usefulness of AFP, AFP-L3, and PIVKA-II, and their combinations in diagnosing hepatocellular carcinoma

Abstract

Alpha-fetoprotein (AFP), Lens culinaris-agglutinin-reactive fraction of AFP (AFP-L3), and protein induced by vitamin K absence or antagonist-II (PIVKA-II) are widely used as tumor markers for the diagnosis of hepatocellular carcinoma (HCC). This study compared the diagnostic values of AFP, AFP-L3, and PIVKA-II individually and in combination to find the best biomarker or biomarker panel.Seventy-nine patients with newly diagnosed HCC and 77 non-HCC control patients with liver cirrhosis were enrolled. AFP, AFP-L3, and PIVKA-II were measured in the same serum samples using microchip capillary electrophoresis and a liquid-phase binding assay on an automatic analyzer. Receiver-operating characteristic curve analyses were also applied to all combinations of the markers.When the 3 biomarkers were analyzed individually, AFP showed the largest area under the receiver-operating characteristic curve (AUC) (0.751). For combinations of the biomarkers, the AUC was highest (0.765) for "PIVKA-II > 40 mAU/mL and AFP > 10 ng/mL." The combination of "PIVKA-II > 40 mAU/mL and AFP > 10 ng/mL and AFP-L3 > 10%" had worse sensitivity and lower AUC (P = 0.001). The highest AUC of a single biomarker was highest for AFP and of a combination was "PIVKA-II > 40 mAU/mL and AFP > 10 ng/mL," with this also being the case when the cut-off value of AFP and AFP-L3 was changed.Alpha-fetoprotein showed the best diagnostic performance as a single biomarker for HCC. The diagnostic value of AFP was improved by combining it with PIVKA-II, but adding AFP-L3 did not contribute to the ability to distinguish between HCC and non-HCC liver cirrhosis. These findings were not altered when the cut-off value of AFP and AFP-L3 was changed.

Figure 1

Comparisons of AUC values of the biomarkers. (A) AUC values of biomarkers individually (no significant differences). (B) AUC values of combinations using “or” (no significant differences). (C) AUC values of combinations using “and” (“AFP and PIVKA-II” vs “AFP and PIVKA-II and AFP-L3”; P = 0.001). AFP = alpha-fetoprotein, AUC = area under the curve, PIVKA-II = protein induced by vitamin K absence or antagonist-II.

Figure 2

The correlation between serum levels of each biomarker. (A) AFP and AFP-L3 (r = 0.735, P < 0.001). (B) PIVKA-II and AFP (r = 0.422, P < 0.001). (C) PIVKA-II and AFP-L3 (r = 0.432, P < 0.001). AFP = alpha-fetoprotein, PIVKA-II = protein induced by vitamin K absence or antagonist-II.

Figure 3

Comparisons of AUC values of the biomarkers for an AFP cut-off of 20 ng/mL. (A) AUC values of biomarkers individually (AFP vs AFP-L3; P = 0.005). (B) AUC values of combinations using “or” (no significant differences). (C) AUC values of combinations using “and” (“PIVKA-II and AFP” vs “PIVKA-II and AFP-L3”; P = 0.010; “PIVKA-II and AFP” vs “PIVKA-II and AFP and AFP-L3”; P < 0.001). AFP = alpha-fetoprotein, AUC = area under the curve, PIVKA-II = protein induced by vitamin K absence or antagonist-II.

Figure 4

Comparisons of AUC values of the biomarkers for an AFP-L3 cut-off of 7%. (A) AUC values of biomarkers individually (no significant differences). (B) AUC values of combinations using “or” (no significant differences). (C) AUC values of combinations using “and” (“PIVKA-II and AFP” vs “PIVKA-II and AFP and AFP-L3”; P = 0.008). AFP = alpha-fetoprotein, AUC = area under the curve, PIVKA-II = protein induced by vitamin K absence or antagonist-II.