Usefulness of determining a protein induced by vitamin K absence in detection of hepatocellular carcinoma

Protein induced by vitamin K absence or antagonist II (PIVKA II), also called des-gamma carboxy prothrombin (DCP), is a sensitive marker for the diagnosis of hepatocellular carcinoma (HCC), in Japan and the United States since the sensitive kits were available (1998). PIVKA II is not used in clinical diagnosis in China so far. The aim of this study was to assess the diagnostic value of PIVKA II in Chinese patients with HCC. Serum PIVKA II and alpha-fetoprotein (AFP) levels were determined in 60 patients with HCC and 30 patients with cirrhosis not carrying HCC. The mean serum concentration of PIVKA II in HCC patients (784.3 +/- 1364.1 mean +/- s) was higher than that in cirrhosis patients (16.1 +/- 31.7); this difference was highly significant (P < 0.0001). When the cutoff level of 40 mAU/ml was used as the level of discriminating HCC from cirrhosis, 51.7% of patients (31/60) with HCC had PIVKA II values above this level (sensitivity). Only 4 patients with cirrhosis had such high PIVKA II levels. Thus, the specificity of this test was 86.7% (26/30). Total accuracy was 62.2% [(31 + 26)/(60 + 30)]. Seven of 19 small HCCs (36.84%) had PIVKA II values above the cutoff level. Concentrations of AFP above 20 ng/ml were observed in 34 of 60 patients with HCC (56.7%) and in 11 patients with cirrhosis (36.7%). Eleven of 26 patients with HCC (46.2%) without increased AFP had concentrations of PIVKA II greater than 40 mAU/ml. No significant correlation was found between serum levels of AFP and PIVKA II that were measured in 60 HCC patients (rs = 0.101, P = 0.247). Combining the information from PIVKA II and AFP showed an increase of approximately 21.6% over AFP and 26.7% over PIVKA II alone. For small HCC patients, combining the information from PIVKA II and AFP showed an increase of approximately 15.8% over AFP alone and 21.1% over PIVKA II alone. PIVKA II is a useful early diagnostic marker for HCC and may be more sensitive when combined with AFP in Chinese patients.