Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA.
Aliment Pharmacol Ther. 2013 Mar;37(5):546-54. doi: 10.1111/apt.12218. Epub 2013 Jan 24.
Current approaches to the detection of colorectal neoplasia associated with inflammatory bowel disease (IBD-CRN) are suboptimal.
To test the feasibility of using stool assay of exfoliated DNA markers to detect IBD-CRN.
This investigation comprised tissue and stool studies. In the tissue study, gene sequencing and methylation assays were performed on candidate genes using tissue DNA from 25 IBD-CRNs and from 25 IBD mucosae without CRN. Mutations on p53, APC, KRAS, BRAF or PIK3CA genes were insufficiently informative, but several aberrantly methylated genes were highly discriminant. In the stool study, we evaluated candidate methylated genes (vimentin, EYA4, BMP3, NDRG4) in a prospective blinded study on buffered stools from 19 cases with known IBD-CRN and 35 age- and sex-matched IBD controls without CRN. From stool-extracted DNA, target genes were assayed using quantitative allele-specific real-time target and signal amplification method.
IBD-CRN cases included 17 with ulcerative colitis (UC) and two with Crohn's disease (CD); nine had cancer and 10 had dysplasia. Controls included 25 with UC and 10 with CD. Individually, BMP3, vimentin, EYA4 and NDRG4 markers showed high discrimination in stools with respective areas under the ROC curve of 0.91, 0.91, 0.85 and 0.84 for total IBD-CRN and of 0.97, 0.97, 0.95 and 0.85 for cancer. At 89% specificity, the combination of BMP3 and mNDRG4 detected 9/9 (100%) of CRC and 80% of dysplasia, 4/4 (100%) of high grade and 4/6 (67%) of low grade.
These findings demonstrate the feasibility of stool DNA testing for non-invasive detection of colorectal neoplasia associated with inflammatory bowel disease.
目前针对与炎症性肠病（IBD）相关的结直肠肿瘤（IBD-CRN）的检测方法并不理想。
检测脱落 DNA 标志物粪便检测法用于诊断 IBD-CRN 的可行性。
本研究包括组织学和粪便学研究。在组织学研究中，对 25 例 IBD-CRN 组织和 25 例无 CRN 的 IBD 黏膜组织的 DNA 进行基因测序和甲基化分析。p53、APC、KRAS、BRAF 或 PIK3CA 基因突变的信息量不足，但一些异常甲基化基因具有高度鉴别性。在粪便学研究中，我们在一项前瞻性、盲法研究中评估了候选甲基化基因（波形蛋白、EYA4、BMP3、NDRG4）在已知患有 IBD-CRN 的 19 例病例和 35 例年龄、性别匹配的无 CRN 的 IBD 对照者的缓冲粪便标本中的应用。从粪便中提取的 DNA 采用实时定量等位基因特异性目标和信号扩增法检测靶基因。
IBD-CRN 病例包括 17 例溃疡性结肠炎（UC）和 2 例克罗恩病（CD）；9 例为癌症，10 例为异型增生。对照组包括 25 例 UC 和 10 例 CD。单独来看，BMP3、波形蛋白、EYA4 和 NDRG4 标志物在总 IBD-CRN 时的 ROC 曲线下面积分别为 0.91、0.91、0.85 和 0.84，在癌症时分别为 0.97、0.97、0.95 和 0.85，具有较高的鉴别能力。在特异性为 89%时，BMP3 和 mNDRG4 的联合检测可检出 9/9（100%）的 CRC 和 80%的异型增生，100%的高级别异型增生和 67%的低级别异型增生。
这些发现证明了粪便 DNA 检测用于非侵入性检测与炎症性肠病相关的结直肠肿瘤的可行性。
