Simultaneous measurements of serum alpha-fetoprotein and protein induced by vitamin K absence for detecting hepatocellular carcinoma.  South Tohoku District Study Group. 
We evaluated the measurements of serum alpha-fetoprotein (AFP) and the protein induced by vitamin K absence (PIVKA-II) in 734 patients with chronic hepatitis (CH) and liver cirrhosis (LC) who had been followed-up for the development of hepatocellular carcinoma (HCC).  Serum AFP and PIVKA-II were measured every month and abdominal ultrasonography was performed every 3 months.  Youden's index (sensitivity + specificity -1) was calculated.  On an average follow-up period of 374.5 days, HCC was detected in three HBsAg-positive LC patients (10.0%/yr), four anti-HCV-positive CH patients (1.35%/yr), 21 anti-HCV-positive LC patients (7.8%/yr), and one patient with both HBsAg- and anti-HCV-positive LC (22.7%/yr).  At the time of HCC detection, the size of HCC was 4.7+/-0.6 (mean +/- SD) cm in HBsAg-positive patients and 2.4+/-1.3 cm in anti-HCV-positive patents.  Cut-off values of 20 ng/ml for AFP (Youden's index = 0.422) and 60 mAU/ml for PIVKA-II (Youden's index = 0.316) gave the highest index for each marker.  When these two markers were combined, cut-off values of 40 ng/ml for AFP and 80 mAU/ml for PIVKA-II gave the highest index (Youden's index = 0.500, sensitivity = 65.5%, specificity = 85.5%, positive predictable value = 14.8%, negative predictable value = 98.3%).  The levels of AFP or PIVKA-II increased within three months before the detection of HCC.  Simultaneous measurements of serum AFP and PIVKA-II levels that are performed every 3 months are useful for detecting a developing HCC.  The optimal cut-off values for AFP and PIVKA-II may be 40 ng/ml and 80 mAU/ml, respectively.