甲胎蛋白对原发性肝癌及肝硬化诊断价值研究

Value of α-fetoprotein in diagnosis of primary liver cancer and cirrhosis

目的研究甲胎蛋白(AFP)诊断肝癌和肝硬化的价值。方法2005年1月～2007年12月住院患者60例,分为肝癌组及肝硬化组。AFP检测采用ELISA双抗体夹心法,按说明书操作。AFP、年龄、肝功能等差异比较使用Wilcoxon秩和检验;ROC曲线利用Fisher线性判别分析绘制出。结果ROC曲线显示灵敏度和特异度组合最佳时,AFP诊断肝癌其临界值为110μg/L,此时灵敏度为73.4%,特异度为93.3%,ROC曲线下的面积是0.822,阳性预测值为91.3%,阴性预测值为76.7%。若采用临床所使用的诊断临界值20μg/L,则其诊断灵敏度为80.0%,特异度则下降为46.7%。灵敏度虽有所提高,但差异无统计学意义(P>0.05),特异度显著下降(P<0.001)。结论采用AFP 110μg/L诊断肝癌价值较优,但是仍需大量的样本来验证。

Objective To study the diagnostic value of at -fetoprotein （AFP） in determination of liver cancer and cirrhosis, that is, to determine the best boundary value of AFP for diagnosis through a diagnostic test. Methods All patients were selected from inpatients from January 2005 to December 2007 in this hospital, and were divided into liver cancer group and liver cirrhosis group. Double - antibody sandwich ELISA was used to determine the serum contents of AFP in accordance with operation instructions. The differences in AFP, age, and liver function were compared using the Wilcoxon rank sum test. An ROC curve was created using Fisher linear discriminant analysis. Results As shown in the ROC curve, the critical value of AFP for diagnosis of liver cancer is 110μg/L which resulted in the best combination of specificity （93.3%） and sensitivity（73.4% ）. The area under the ROC curve was O. 822, with the positive predictive value of 91.3 % and the negative predictive value of 76.7 %. However, when 20μg/L was set as the criti- cal value, the sensitivity increased （80.0%, P 〉 O. 05 ） but the specificity decreased markedly （46.7%, P 〈 O. 001 ）. Conclusions 110μg/L is an optimal value for diagnosis of liver cancer, which requires further validation by a large case study.