Published online Jun 28, 2022. doi: 10.3748/wjg.v28.i24.2705
Peer-review started: December 4, 2021
First decision: January 8, 2022
Revised: January 14, 2022
Accepted: May 13, 2022
Article in press: May 13, 2022
Published online: June 28, 2022
Processing time: 202 Days and 4.6 Hours
Stool DNA (sDNA) methylation analysis is a promising, noninvasive approach for colorectal cancer screening; however, reliable biomarkers for detecting early-stage colon cancer (ECC) are lacking, particularly in the Chinese population.
To identify a novel stool-based assay that can improve the effectiveness of ECC screening.
A blinded case-control study was performed using archived stool samples from 125 ECC patients, and 125 control subjects with normal colonoscopy. The cohort was randomly divided into training and test sets at a 1.5:1 ratio. Targeted bisulfite sequencing (TBSeq) was conducted on five pairs of preoperative and postop-erative sDNA samples from ECC patients to identify DNA methylation biomarkers, which were validated using pyrosequencing. By logistic regression analysis, a multiplex stool-based assay was developed in the training set, and the detection performance was further assessed in the test set and combined set. The
Following TBSeq, three hypermethylated cytosine-guanine sites were selected as biomarkers, including paired box 8, Ras-association domain family 1 and secreted frizzled-related protein 2, which differed between the groups and were involved in important cancer pathways. An sDNA panel containing the three biomarkers was constructed with a logistic model. Receiver operating characteristic (ROC) analysis revealed that this panel was superior to the fecal immunochemical test (FIT) or serum carcinoembryonic antigen for the detection of ECC. We further found that the combination of the sDNA panel with FIT could improve the screening effectiveness. In the combined set, the sensitivity, specificity and area under the ROC curve for this multiplex assay were 80.0%, 93.6% and 0.918, respectively, and the performance remained excellent in the subgroup analysis by tumor stage. In addition, the detection sensitivity did not differ with tumor site, tumor stage, histological differentiation, age or sex, but was significantly higher in T4 than in T1-3 stage tumors (P = 0.041).
We identified a novel multiplex stool-based assay combining sDNA methylation biomarkers and FIT, which could detect ECC with high sensitivity and specificity throughout the colon, showing a promising application perspective.
Core Tip: Stool DNA (sDNA) methylation analysis has a promising application in the early diagnosis of colorectal cancer. However, reliable biomarkers for detecting early-stage colon cancer (ECC) are lacking. In this study, by targeted bisulfite sequencing, we identified a novel multiplex stool-based assay combining three sDNA methylation biomarkers and fecal immunochemical test. Further validation in larger samples by pyrosequencing showed that it enabled the diagnosis of ECC with high sensitivity and specificity throughout the colon. To our knowledge, this is the first study to focus on ECC screening in China.