粪便具核梭杆菌与clbA+大肠埃希菌DNA检测在结直肠癌诊断中的价值

Role of fecal DNA level of Fusobacterium nucleatum and clbA+ Escherichia coli in the diagnosis of colorectalcancer

目的探讨粪便具核梭杆菌与clbA+大肠埃希菌检测诊断结直肠癌的价值。方法采用实时荧光定量聚合酶链反应(PCR)检测58位健康对照者、38例腺瘤患者及115例肠癌患者粪便样本中具核梭杆菌与clbA+大肠埃希菌DNA相对表达量。结果clbA+大肠埃希菌DNA相对表达量健康对照组为0.0016(0.00046~0.0049)、腺瘤组为0.0026(0.00045~0.0088)、肠癌组为0.0063(0.0020~0.036),具核梭杆菌DNA相对表达量健康对照组为0.0010(0.00031~0.0029)、腺瘤组为0.0033(0.0011~0.0110)、肠癌组为0.0064(0.0029~0.0120)。健康对照组、肠癌组clbA+大肠埃希菌及具核梭杆菌DNA相对表达量差异有统计学意义(P<0.0001)。受试者工作特征(ROC)曲线分析结果显示clbA+大肠埃希菌及具核梭杆菌诊断肠癌的曲线下面积(AUC)分别为0.712、0.750,最佳临界值分别为0.0033、0.0023,敏感性分别为64.32%、80.87%,特异性分别为65.52%、68.97%。clbA+大肠埃希菌及具核梭杆菌阳性检出率在早期和晚期肠癌中差异无统计学意义(P>0.05),二者对早期肠癌的检出率分别为75.7%、80.5%,较癌胚抗原(CEA)及粪便隐血试验(FOBT)敏感性高。结论具核梭杆菌与clbA+大肠埃希菌在结直肠癌患者粪便中显著富集,可作为结直肠癌潜在的早筛生物标志物。

Objective To investigate the role of fecal DNA level of Fusobacterium nucleatum and clbA+Escherichia coli in the diagnosis of colorectal cancer.Methods Real-time fluorescence quantitation polymerase chain reaction(PCR)was used to determine the DNA level of Fusobacterium nucleatum and clbA+Escherichia coli in 58 healthy subjects,38 adenoma patients and 115 colorectal cancer patients.Results The DNA levels of clbA+Escherichia coli were 0.0016(0.00046-0.0049)in healthy control group,0.0026(0.00045-0.0088)in adenoma group and 0.0063(0.0020-0.036)in colorectal cancer group.Those of Fusobacterium nucleatum were 0.0010(0.00031-0.0029)in healthy control group,0.0033(0.0011-0.0110)in adenoma group and 0.0064(0.0029-0.0120)in colorectal cancer group.The DNA level of Fusobacterium nucleatum and clbA+Escherichia coli in colorectal cancer group had statistical significance compared with healthy control group(P<0.0001).Receiver operating characteristic(ROC)curve analysis showed that the areas under curves(AUC)of clbA+Escherichia coli and Fusobacterium nucleatum in the diagnosis of colorectal cancer were 0.712 and 0.750,respectively.The optimal cut-off values were 0.0033 and 0.0023,the sensitivities were 64.32%and 80.87%,and the specificities were 65.52%and 68.97%,respectively.The positive rates of clbA+Escherichia coli and Fusobacterium nucleatum in the early stage of colorectal cancer were 75.7%and 80.5%,which were higher than those of carcinoembryonic antigen(CEA)and fecal occult blood test(FOBT),and there was no statistical significance between early and advanced stages(P>0.05).Conclusions The clbA+Escherichia coli and Fusobacterium nucleatum are abundant in feces from colorectal cancer patients,which may be used as potential early determination biomarkers in colorectal cancer.