Mita Y, Aoyagi Y, Yanagi M, Suda T, Suzuki Y, Asakura H
Department of Internal Medicine, Niigata University School of Medicine, Japan.
Cancer. 1998 May 1;82(9):1643-8. doi: 10.1002/(sici)1097-0142(19980501)82:9<1643::aid-cncr8>3.0.co;2-b.
Measurements of serum concentrations of des-gamma-carboxy prothrombin (DCP) are widely used for diagnosing hepatocellular carcinoma (HCC). However, the DCP is not always sensitive enough to detect small HCCs. In the current study, the authors investigated the usefulness of DCP in the early diagnosis of HCC, using a more sensitive enzyme immunoassay than is conventionally employed.
The authors examined 148 serum samples with DCP concentrations from a conventional assay of less than 100 mAU (arbitrary unit)/mL from 91 patients with HCC and 57 with cirrhosis. DCP concentrations were determined by a more sensitive enzyme immunoassay (ED-036 kit, Eisai Laboratory, Tokyo, Japan) with a minimal detection level of 10 mAU/mL. Ninety-one HCC patients had 43 solitary small HCCs (with a greatest dimension of less than 2 cm). Of these 43 HCCs, 12 were well differentiated.
The mean serum concentration of DCP in HCC (48.3 +/- 24.3, mean +/- standard deviation [SD]) was higher than in cirrhosis (20.3 +/- 10.3); this difference 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 cirrhosis, 62% of patients (56 of 91) with HCC had DCP values above this level (sensitivity). However, only three patients with cirrhosis had higher 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.
The results of this study indicate that DCP determination by sensitive enzyme immunoassay is useful in the early diagnosis of HCC because a high specificity is maintained.
血清去γ-羧基凝血酶原（DCP）浓度测定广泛用于肝细胞癌（HCC）的诊断。然而，DCP检测小肝癌时的敏感性并不总是足够高。在本研究中，作者使用了一种比传统方法更灵敏的酶免疫测定法，研究了DCP在HCC早期诊断中的作用。
作者检测了91例HCC患者和57例肝硬化患者的148份血清样本，这些样本用传统方法检测的DCP浓度低于100 mAU（任意单位）/mL。采用一种更灵敏的酶免疫测定法（ED-036试剂盒，日本东京卫材实验室）测定DCP浓度，最低检测水平为10 mAU/mL。91例HCC患者中有43例为孤立性小肝癌（最大直径小于2 cm）。在这43例肝癌中，12例为高分化。
HCC患者血清DCP平均浓度（48.3±24.3，平均值±标准差[SD]）高于肝硬化患者（20.3±10.3）；差异具有统计学意义。当将40 mAU/mL的暂定临界值（几乎相当于肝硬化患者的平均值+2SD）作为区分HCC和肝硬化的水平时，62%（91例中的56例）的HCC患者DCP值高于该水平（敏感性）。然而，只有3例肝硬化患者DCP水平较高。因此，该检测的特异性为95%（57例患者中的54例）。总准确率为74%（56 + 54/91 + 57）。43例孤立性小肝癌中有23例（53%）DCP值高于临界值。此外，12例最大直径小于2 cm的小的、高分化HCC中有7例（58%）DCP值较高。
本研究结果表明，通过灵敏的酶免疫测定法测定DCP在HCC的早期诊断中是有用的，因为其保持了高特异性。
