Detection of aberrant methylation in fecal DNA as a molecular screening tool for colorectal cancer and precancerous lesions

AIM: To investigate the feasibility of detecting methylated fecal DNA as a screening tool for colorectal carcinoma (CRC) and precancerous lesions. METHODS: Methylated secreted frizzled-related protein gene 2 (SFRP2), hyperplastic polyposis protein gene (HPP1) and O-6-methylguanine-DNA methyltransferase gene (MGMT) in stools from 52 patients with CRC, 35 patients with benign colorectal diseases and 24 normal individuals were analyzed using methylation-specific PCR. RESULTS: Methylated SFRP2, HPP1 and MGMT were detected in 94.2%, 71.2%, 48.1% of CRC patients and 52.4%, 57.1%, 28.6% of adenoma patients, respectively. The overall prevalence of fecal DNA with at least one methylated gene was 96.2% and 81.8% in patients with CRC and precancerous lesions, respectively. In contrast, only one of the 24 normal individuals revealed methylated DNA. These results indicated a 93.7% sensitivity and a 77.1% specificity of the assay for detecting CRC and precancerous lesions. CONCLUSION: Methylation testing of fecal DNA using a panel of epigenetic markers may be a simple and promising non-invasive screening method for CRC and precancerous lesions. (C) 2007 The WJG Press. All rights reserved.