THE USEFULNESS OF DETERMINING DES-GAMMA-CARBOXY PROTHROMBIN BY SENSITIVE ENZYME-IMMUNOASSAY IN THE EARLY DIAGNOSIS OF PATIENTS WITH HEPATOCELLULAR-CARCINOMA

BACKGROUND. Measurements of serum concentrations of des-gamma-carboxy prothrombin (DCP) are widely used for diagnosing hepatocellular carcin oma (HCC). However, the DCP is not always sensitive enough to detect s mall HCCs. In the current study, the authors investigated the usefulne ss of DCP in the early diagnosis of HCC, using a more sensitive enzyme immunoassay than is conventionally employed. METHODS. The authors exa mined 148 serum samples with DCP concentrations from a conventional as say of less than 100 mAU (arbitrary unit)/mL from 91 patients with HCC and 57 with cirrhosis. DCP concentrations were determined by a more s ensitive enzyme immunoassay (ED-036 kit, Eisai Laboratory, Tokyo, Japa n) with a minimal detection level of 10 mAU/mL. Ninety-one HCC patient s had 43 solitary small HCCs (with a greatest dimension of less than 2 cm). Of these 43 HCCs, 12 were well differentiated. RESULTS. The mean serum concentration of DCP in HCC (48.3 +/- 24.3, mean +/- standard d eviation [SD]) was higher than in cirrhosis (20.3 +/- 10.3); this diff erence was statistically significant. When the tentative cutoff level of 40 mAU/mL (almost corresponding to the mean value + 2SD in patients with cirrhosis) was used as the level of discriminating HCC from cirr hosis, 62% of patients (56 of 91) with HCC had DCP values above this l evel (sensitivity). However, only three patients with cirrhosis had hi gher DCP levels. Thus, the specificity of this test was 95% (54 of 57 patients). The total accuracy was 74% (56 + 54/91 + 57). Twenty-three of 43 solitary small HCCs (53%) had DCP values above the cutoff level. Furthermore, 7 of 12 (58%) small, well-differentiated HCCs less than 2 cm in greatest dimension had higher DCP values. CONCLUSIONS. The res ults of this study indicate that DCP determination by sensitive enzyme immunoassay is useful in the early diagnosis of HCC because a high sp ecificity is maintained. (C) 1998 American Cancer Society.