Usefulness of simultaneous determination of alpha-fetoprotein and des-gamma-carboxy prothrombin in hepatocellular carcinoma.

Serum gamma-fetoprotein (AFP) and plasma des-gamma-carboxy prothrombin (DCP), a protein induced by vitamin K absence or antagonist II (PIVKA-II) levels, were measured in 197 patients with primary hepatocellular carcinoma (HCC). DCP levels were determined by conventional enzyme immunoassay kit (E-1023) and a newly developed high-sensitivity kit using the avidin-biotin complex method. Cut-off levels of AFP and DCP by the E-1023 kit and of DCP by the high-sensitivity kit were put at 100 ng/ml, 0.1 arbitrary unit (AU)/ml, and 0.004 AU/ml, respectively. Positive rate of AFP and DCP by the E-1023 kit and the high-sensitivity kit for HCC was 48%, 44%, and 57%, respectively. The positive rate by combination assay with AFP and DCP by the high-sensitivity kit increased up to 73%. There was no correlation between serum levels of AFP and those of plasma DCP. A significant correlation between tumor size and DCP levels was observed, but not with AFP. The postoperative disease-free survival rates of patients in the group with elevated levels of AFP and DCP were lower than those with normal levels of AFP and DCP. There were various patterns of change in the AFP and DCP levels at the time of recurrence compared with preoperative patterns. The combination assay of AFP and DCP levels is useful for the diagnosis, prognosis, and postoperative monitoring for recurrence of HCC.