Des‐gamma‐carboxy prothrombin (DCP) ratio, a novel parameter measured by monoclonal antibodies MU‐3 and 19B7, as a new prognostic indicator for hepatocellular carcinoma

BACKGROUND/AIM: Recently, a novel des-gamma-carboxy prothrombin (DCP) antibody named 19B7 has been developed. It has been reported that the DCP ratio defined by DCP measured by MU-3 antibody/DCP measured by 19B7 antibody demonstrated differences between hepatocellular carcinoma and vitamin K deficiency. The aim of this study was to clarify the relationship between the DCP ratio and tumour malignancy, as well as the prognostic significance of the DCP ratio after hepatectomy for hepatocellular carcinoma. METHODS: From January 1996 to December 1999, 79 patients diagnosed with hepatocellular carcinoma underwent hepatectomy. To detect DCP in the plasma before surgery, we used a new EIA kit, Eitest PIVKA-II kit (Eisai, Tokyo, Japan) with both MU-3 and 19B7 antibody. The DCP ratio was calculated using the formula: DCP ratio = DCP level measured by MU-3 antibody (mAU/ml)/DCP level measured by 19B7 antibody (mAU/ml). Pathologic findings using resected specimens were classified according to the Japanese General Rules for Primary Liver Cancer. RESULTS: Among DCP-positive patients, the DCP ratio was significantly higher in those with tumour thrombus in the portal vein (vp) or with a moderately or poorly differentiated hepatocellular carcinoma than in those without vp or with a well-differentiated carcinoma (P = 0.0162, 0.0109, respectively). Patients with DCP ratio > 3 had a significantly higher incidence of vp than those with DCP ratio 3 (P = 0.0002). This result was the same as in DCP positive cases (P = 0.0027). CONCLUSIONS: The DCP ratio can distinguish DCP produced by hepatoma cells from DCP produced by normal hepatocytes in vitamin K deficiency. The DCP ratio is a useful prognostic indicator that can be assessed before hepatectomy.