A novel method for early detection of colorectal cancer based on detection of methylation of two fragments of syndecan-2 (SDC2) in stool DNA

Abstract

Background Methylated SDC2 has been proved as a diagnostic marker for human colorectal cancer (CRC), noninvasive stool DNA-based methylation testing also emerges as a novel approach for detecting CRC. The aim of this study was to evaluate the clinical performance of stool DNA-based SDC2 methylation test by a new qPCR detection reagent for early detection of CRC. Methods A new qPCR detection reagent contained two differentially methylated regions in SDC2 CpG islands for the detection of CRC was used in this study. Performance of the SDC2 methylation detection reagent was evaluated by analyzing limit of detection, precision, and specificity. The effect of interfering substances on assay performance was also tested. 339 subjects (102 CRC patients, 50 patients with advanced adenomas, 39 patients with non-advanced adenomas, 18 colitis patients and 130 normal individuals) from the China-Japan Friendship Hospital were evaluated. Approximately 2.5 g of stool sample was collected from each participant. Stool DNA was extracted and bisulfite-converted, followed by qPCR assay, which contained two pairs of primers for the methylation detection of two fragments of the SDC2 gene (named SDC2-A and SDC2-B). The diagnostic value of this test in CRC was evaluated by calculating receiver operating characteristic (ROC) curve, and value of the area under the curve (AUC). Results The test kit was able to detect methylated SDC2 in stool DNA samples with concentrations as low as 90 copies/μL in 100% of replicates. The sensitivity for detecting CRC by methylated SDC2-A alone was 85.29% (95% CI 77.03–91.00%) with a specificity of 96.15% (95% CI 91.08–98.58%). The sensitivity by methylated SDC2-B alone was 83.33% (95% CI 74.82–89.42%) with a specificity of 97.69% (95% CI 93.14–99.51%). However, when methylated SDC2-A and methylated SDC2-B were combined, the sensitivity for CRC detection improved to 87.25% (95% CI 79.27–92.53%) with a specificity of 94.62% (95% CI 89.11–97.56%). Further, the detection reagent achieved ROC-AUC 0.874 (95% CI 0.822–0.927) for SDC2-A, 0.906 (95% CI 0.859–0.952) for SDC2-B, and 0.939 (95% CI 0.902–0.977) for SDC2-Combine A&B. Conclusions This study validated the capability of stool DNA-based SDC2 methylation test for early screening of CRC, and combined detection of two fragments of SDC2 gene could improve detection sensitivity.

Methylation of CpG island promoters at ZNF625, LONRF2, SDC2 and WDR17 in a patient with numerous non‑granular type laterally spreading tumors and colorectal cancer: A case report

“…Oh et al first reported the hypermethylation of SDC2 in colorectal adenoma as well as in CRC, indicating its contribution to tumorigenesis (34). Their results have been corroborated by other groups, and various useful evaluation methods using stool samples, blood, and urine have been demonstrated (35)(36)(37)(38)(39)(40). In contrast to many previous reports concerning SDC2 in colorectal adenomas and CRC, little is known about alterations in ZNF625, LONRF2, and WDR17 concerning CRC tumorigenesis.…”

Application and development of noninvasive biomarkers for colorectal cancer screening: a systematic review

“…In another trial, 339 participants (102 with CRC, 50 with AAs, and 130 normal individuals) were enrolled, and two fragments of SDC2 CpG islands ( SDC2-A and SDC2-B ) were detected by qPCR (quantitative real-time PCR). The sensitivity of this test for CRC and AAs improved to 87.25 and 52%, respectively, while the specificity was 94.62% 16 , 19 . Large prospective screening cohorts should be studied to analyze factors, such as geography, age, and sex, that may affect test performance.…”

Colon Cancer Screening Methods: 2023 Update

“…Other noninvasive DNA-based hypermethylated genes that can be found in stool samples are GATA binding protein 4, GATA binding protein 45, Syndecan-2 (SDC2), Methylguanine Methyltransferase (MGMT), Cyclin-Dependent Kinase Inhibitor-2A (CDKN2A), MutL homolog 1 (MLH1), and N-Myc downstream-regulated gene-4 (NDRG-4) [77][78][79][80].…”