Analysis of Syndecan-2 Methylation in Bowel Lavage Fluid for the Detection of Colorectal Neoplasm

BACKGROUND/AIMS: Syndecan-2 (SDC2) methylation was previously reported as a sensitive serologic biomarker for the early detection of colorectal cancer (CRC). The purpose of this study was to investigate whether SDC2 methylation is detectable in precancerous lesions and to determine the feasibility of using SDC2 methylation for the detection of CRC and precancerous lesions in bowel lavage fluid (BLF). METHODS: A total of 190 BLF samples were collected from the rectum at the beginning of colonoscopy from patients with colorectal neoplasm and healthy normal individuals. Fourteen polypectomy specimens were obtained during colonoscopy. A bisulfite pyrosequencing assay and quantitative methylation-specific polymerase chain reaction were conducted to measure SDC2 methylation in tissues and BLF DNA. RESULTS: SDC2 methylation was positive in 100% of villous adenoma (VA) and high-grade dysplasia, and hyperplastic polyp samples; 88.9% of tubular adenoma samples; and 0% of normal mucosa samples. In the BLF DNA test forSDC2 methylation, the sensitivity for detecting CRC and VA was 80.0% and 64.7%, respectively, at a specificity of 88.9%. The BLF of patients with multiple tubular adenomas, single tubular adenoma and hyperplastic polyps showed 62.8%, 26.7% and 28.6% rates of methylation-positive SDC2, respectively. CONCLUSIONS: Our results demonstrated that SDC2 methylation was a frequent event in precancerous lesions and showed high potential in BLF for detecting patients with colorectal neoplasm.