[Comparison of two serological methods in screening gastric cancer and its precancerous condition].

Objective: To compare the diagnostic value of the old "ABC" method [serum pepsinogen(PG) combined with Helicobacter pylori (Hp) IgG antibody] and the new "ABC" method [serum pepsinogen plus gastrin-17(G-17)] in screening gastric cancer and its precancerous condition. Methods: Serum PG, G-17 and Hp-IgG were quantified by enzyme-linked immunosorbent assay (ELISA) in 278 subjects. Subjects were grouped according to the criteria of two methods. The gastroscopy and pathological biopsy were gold standard. Results: The positive rate of old "ABC" method was 74.46% (207/278), which was 54.68% of new "ABC" method (151/278). For the diagnosis of gastric cancer, the sensitivity and specificity of the old "ABC" method were 90.74% and 29.46% respectively, with diagnostic coincidence rate 41.37%. The sensitivity and specificity of the new "ABC" method were 92.59% and 54.46% respectively, with diagnostic coincidence rate 61.87%. As to the diagnosis of pre-cancerous state, the sensitivity and specificity of the old "ABC" method were 75.81% and 36.00%, with diagnostic coincidence rate 58.03%. The sensitivity and specificity of the new "ABC" method were 62.10% and 75.00%, with diagnostic coincidence rate 67.86%. Conclusions: Compared with the old "ABC" method, the new "ABC" method has higher sensitivity, specificity and diagnostic coincidence rate for the diagnosis of gastric cancer, yet higher specificity and lower sensitivity for the diagnosis of precancerous conditions.目的： 初步评价血清胃蛋白酶原联合幽门螺杆菌IgG抗体筛查法（旧"ABC"法）和血清胃蛋白酶原联合胃泌素-17筛查法（新"ABC"法）在胃癌及其癌前状态筛查中的诊断价值。 方法： 采用酶联免疫吸附试验定量检测278例受试者血清胃蛋白酶原、胃泌素-17和幽门螺杆菌IgG抗体水平。分别根据两种血清学筛查方法的分组标准将受试者进行分组，以胃镜及病理结果为金标准，比较两种方法在胃癌及其癌前状态筛查中的诊断效果。 结果： 旧"ABC"法中，血清学结果阳性207例，阳性率为74.46%；新"ABC"法中，血清学结果阳性152例，阳性率为54.68%。在胃癌的预测方面，旧"ABC"法血清学结果阳性预测胃癌的灵敏度为90.74%，特异度为29.46%，诊断符合率为41.37%；新"ABC"法血清学结果阳性预测胃癌的灵敏度为92.59%，特异度为54.46%，诊断符合率为61.87%。在胃癌的癌前状态预测方面，旧"ABC"法的灵敏度为75.81%，特异度为36.00%，诊断符合率为58.03%；新"ABC"法的灵敏度为62.10%，特异度为75.00%，诊断符合率为67.86%。 结论： 与旧"ABC"法相比，新"ABC"法对胃癌诊断的灵敏度、特异度和诊断符合率较高，对胃癌的癌前状态诊断的特异度较高而灵敏度稍低。.