图象自动分析检测MG7抗原表达预测胃癌高危价值探讨

DetectionofMG7AntigenExpressioninPredictingHigh┐RiskinGastricCancerbyAutomaticImageAnalysis

为探讨胃癌单克隆抗原ＭＧ７在胃粘膜不典型增生中的预测价值，应用ＭＧ７抗体进行ＡＢＣ免疫组化染色，并用计算机图象分析系统，对７２例有随访结果的胃粘膜不典型增生标本的ＭＧ７抗原表达进行了定量分析。通过计算约登指数及绘制受试者工作特征曲线，初步探讨了ＭＧ７表达的高危界值。免疫组化染色结果显示，癌变组３４例标本中有２４例表达阳性（７０．６％）。未癌变组３８例标本中仅７例呈阳性表达（１８．４％），两组比较差异有显著性。图象分析等结果显示：ＭＧ７Ａｇ的平均灰度值≥０．１９为高危界值，以此值作为判定不典型增生是否具有癌变倾向的依据，其灵敏度＝８２．４％，特异度＝７８．９％，准确度＝８０．６％。结论：ＭＧ７Ａｇ的表达程度和胃粘膜不典型增生癌变关系密切，ＭＧ７Ａｇ表达阳性的胃粘膜不典型增生病例，尤其是灰度值≥０．１９者，是具有潜在癌变倾向的高危人群，对这些病人进行严密的随访监测，可提高早期胃癌检出率。

Tostudythepredictivevalueofgastriccancermonoclonalantigen(MG7-Ag)inde-tectingatypicalhyperplasiaofgastricmucosa,itsexpressionin72casesoftheilnesswithfolow-upwasdeterminedquantitativelybycomputer-aidedimageanalysissystemwithimmunohistochemicalstainforMG7antibody.CriticalvalueofMG7-Agexpressionforhigh-riskingastriccancerwasex-ploredpreliminarilybyYoudenindexandreceiveroperatorcharacteristiccurve.Resultsofimmuno-histochemicalstainshowedtherewere24withpositiveexpression(70.6%)in34cancerouscases,andonlysevenin38non-cancerouscases(18.4%),withasignificantdiference.ImageanalysisshowedanaverageMG7-Agdensityequaltoorgreaterthan0.19wasregardedasthecriticalvalueforhigh-riskingastriccancer,whichcouldbeusedtodiscriminateatypicalhyperplasiafromcancera-tion,withasensitivityof82.4%,aspecificityof78.9%,andanaccuracyof80.6%.Thus,itcouldbeconcludedthatMG7-Agexpressioncorrelatedcloselywithcancerationofgastricatypicalhyperpla-sia,positiveMG7-Agexpressioningastricmucosaofpatientswithatypicalhyperplasia,especialyincaseswithadensityofequaltoorgreaterthan0.19,wasanindicatorforhighriskincanceration.Iftheyareputunderstrictfolow-up,earlydetectionofgastriccancerwilbeimproved.