粪便SDC2和NDRG4基因甲基化检测在结直肠癌筛查中的应用分析

Application of SDC2 and NDRG4 gene methylation detection in colorectal cancer screening

目的:有效的筛查能显著降低结直肠癌的发病率和死亡率。本研究通过SDC2和NDRG4基因粪便甲基化水平与结直肠癌的关联性分析,评价其在结直肠癌筛查中的临床价值。方法:收集2019年1月1日~2020年12月31日湖南省人民医院就诊的49例样本,其中结直肠癌患者16例,结直肠癌术后化疗患21例,结直肠息肉患者12例,采用荧光定量PCR法检测粪便中SDC2和NDRG4基因甲基化状态,同时采用化学发光法检测血清肿瘤标志物癌胚抗原(carcinoembryonicantigen,CEA)和糖类抗原19-9(carbohydrateantigen199,CA19-9),分析检测结果与临床病症的关联性。结果:结直肠癌患者组SDC2基因甲基化阳性率为75%,结直肠癌术后化疗组阳性率为9,52%,直肠息肉组阳性率为0%,3组间比较,差异有统计学意义。结直肠癌组SDC2基因甲基化阳性率高于结直肠癌术后化疗组阳性率,差异有统计学意义。SDC2联合NDRG4基因甲基化检测阳性检出率最高。SDC2/NDRG4基因甲基化检测灵敏度分别为75%、25%、75%,特异度为93.94%、100%、93.94%,CEA、CA19-9、CEA/CA19-9检测灵敏度62.5%、37.5%、68.75%,特异度为84.85%、87.88%、78.79,NDRG4特异度高于SDC2、SDC2/NDRG4、CEA、CA19-9、CEA/CA19-9,SDC2联合NDRG4基因甲基化检测阳性预测值(85.71%)及阴性预测值最高(88.57%),受试者工作曲线(ROC)分析显示,SDC2联合NDRG4基因甲基化检测最高(0.905)。结论:SDC2基因甲基化检测对结直肠癌的阳性检出率优于NDRG4基因甲基化检测,SDC2和NDRG4甲基化联合检测诊断性能最高,SDC2和NDRG4可作为结直肠癌筛查和预后判断的有效指标。

Objective Effective screening can significantly reduce the incidence and mortality of colorectal cancer.In this study,the clinical value of SDC2 and NDRG4 genes in colorectal cancer screening was evaluated by analyzing the correlation between fecal methylation levels of SDC2 and NDRG4 genes and colorectal cancer.Methods A total of 49 samples were collected from Hunan Provincial People’s Hospital from January 1,2019 to December 31,2020,including 16 patients with colorectal cancer,21 patients with postoperative chemotherapy of colorectal cancer,and 12 patients with colorectal polyps.The methylation status of SDC2 and NDRG4 genes in feces was detected by fluorescence quantitative PCR.Serum tumor markers carcinoembryonicantigen(CEA)and carbohydrateantigen 19-9(carbohydrateantigen199,CA19-9)were determined by chemiluminescence assay,and the correlation between the results and clinical symptoms was analyzed.Results The positive rate of SDC2 gene methylation was 75%in the colorectal cancer group,9.52%in the postoperative chemotherapy group and 0%in the rectal polyp group.The difference between the three groups was statistically significant.The positive rate of SDC2 gene methylation in colorectal cancer group was higher than that in postoperative chemotherapy group,and the difference was statistically significant.P The positive detection rate of SDC2 combined with NDRG4 gene methylation was the highest.SDC2/NDRG4 methylation detection sensitivity was 75%,25%,75%,specificity was 93.94%,100%,93.94%,CEA,CA19-9,CEA/CA19-9 detection sensitivity 62.5%,37.5%,68.75%,respectively.The specificity of NDRG4 was higher than that of SDC2,SDC2/NDRG4,CEA,CA19-9 and CEA/CA19-9.The positive predictive value(85.71%)and negative predictive value(88.57%)of SDC2 combined with NDRG4 methylation test were the highest.Receiver operating characteristic(ROC)analysis showed that SDC2 combined with NDRG4 gene methylation was the highest(0.905).Conclusion The positive detection rate of SDC2 gene methylation is better than that of NDRG4 gene methylation in colorectal cancer.The combined detection of SDC2 and NDRG4 methylation has the highest diagnostic performance.SDC2 and NDRG4 methylation can be used as effective indicators for colorectal cancer screening and prognosis.