[Comparison of different serological methods in screening early gastric cancer].

Objective: To compare the consistency and detection rate of early gastric cancer (EGC) of three different methods including anti-Helicobacter pylori (Hp) antibody combined with pepsinogen (PG) (ABC method), serum PG combined with gastrin-17 (G-17) (new ABC method) and the new scoring system. Methods: Serological tests were performed in Zhejiang population, which divided the subjects into low risk, intermediate risk and high risk groups. High risk subjects were examined by endoscopic and pathological examination. SPSS19.0 were used to evaluate the consistency of three methods. According to the receiver operating characteristic (ROC) curve, the ratio of G-17 to PG (PGR) was calculated for the optimal diagnostic cut-off value of EGC. Results: A total of 30 126 subjects were recruited. Based on the data of ABC method, the proportions of low risk, intermediate risk and high risk group were 15 368 (51.01%), 13 246 (43.97%), and 1 512 (5.02%), respectively. These proportions by the new ABC method were 20 584 (68.32%), 8 990 (29.84%), 552 cases (1.83%), respectively. By new scoring system, these were 20 810 (69.08%), 8 059 (26.75%), and 1 257 (4.17%), respectively. Among them, 1 263 subjects underwent endoscopy and 22 cases (1.74%) were finally diagnosed as gastric cancer including 19 EGC (86.4%). There were 1 case (0.35%), 14 cases (1.84%), and 7 cases (3.21%) with gastric cancer in low risk, intermediate risk, and high risk groups by ABC methods, respectively. Gastric cancer patients were 7 (1.68%), 10 (1.38%), and 5 (4.10%) in three groups respectively by new ABC methods. Via new scoring system, gastric cancer were detected in 5 (0.66%), 9 (2.22%), and 8 (7.84%) patients of three risk groups respectively. The consistency of three screening methods was poor. The detection rate of gastric cancer in high risk group was higher than that in the other two (P<0.05). The area under the curve (AUC) for diagnosis of gastric cancer by G-17 and PGR was 0.588 and 0.729, respectively. According to the PGR cut-off value determined by the fitted model, the incidence of gastric cancer in the low, intermediate and high risk groups was 0.94%, 1.97%, and 6.31%, respectively. When the cut-off value is PGR<4.135, the sensitivity is 0.855 and the specificity is 0.545. Conclusion: The new scoring system has a better predictive value in EGC screening. The detection rate of EGC in high risk group is higher than that in low and intermediate risk groups.目的： 比较血清幽门螺杆菌（Hp）抗体联合胃蛋白酶原（PG）（ABC法）、血清PG联合胃泌素-17（G-17）（新ABC法）和新胃癌筛查评分系统（简称新评分系统）3种危险分层方法在人群早期胃癌筛查中的作用，评价3种方法的一致性。 方法： 对浙江基层人群进行早期胃癌筛查，所有受试者先行血清学检查，再对高危人群进行内镜及病理学检查，以病理学诊断为胃癌诊断的金标准。3种血清学筛查方法均将人群分为低危组、中危组和高危组，计算3种筛查方法各危险分层的比例和胃癌的检出率，评价筛查方法的优缺点和一致性，根据受试者工作特征（ROC）曲线计算G-17和胃蛋白酶原比值（PGR）诊断胃癌的最佳临界值。 结果： 共纳入30 126例受试者。ABC法中，低、中、高危组受试者分别为15 368例（51.01%）、13 246例（43.97%）和1 512例（5.02%）；新ABC法中，低、中、高危组受试者分别为20 584例（68.32%）、8 990例（29.84%）和552例（1.83%）；新评分系统中，低、中、高危组受试者分别为20 810例（69.08%）、8 059例（26.75%）和1 257例（4.17%）。通过血清学初筛，最终1 263例受试者接受内镜和病理学检查，检出胃癌22例（1.74%），其中早期胃癌19例，占86.4%。ABC法中，低、中、高危组胃癌检出分别为1例（0.35%）、14例（1.84%）和7例（3.21%）；新ABC法中，低、中、高危组胃癌检出分别为7例（1.68%）、10例（1.38%）和5例（4.10%）；新评分系统中，低、中、高危组胃癌检出分别为5例（0.66%）、9例（2.22%）和8例（7.84%）。3种筛查方法的一致性较差。新评分系统的高危组的胃癌检出率高于低危、中危组，差异有统计学意义（P均<0.05）。拟合ROC曲线分析G-17和PGR诊断胃癌的曲线下面积（AUC）分别为0.588和0.729。根据本研究拟合模型确定的最佳临界值（PGR<4.135），低、中、高危组的胃癌检出率分别为0.94%、1.97%和6.31%。当以PGR<3.890为临界值时，诊断胃癌的敏感度为0.880，特异度为0.409；当以PGR<4.135为临界值时，诊断胃癌的敏感度为0.855，特异度为0.545。在这2种PGR临界值下，高危组患者胃癌检出率均高于低、中危组。 结论： 3种血清学筛查方法的一致性较差。新评分系统在早期胃癌筛查中有较高的价值，其高危组的早期胃癌检出率高于低、中危组。.