Stool DNA methylation analysis in the diagnosis of colorectal cancer / 中华检验医学杂志

ABSTRACT

Objective To evaluate the possibility of methylation analysis of secreted frizzled-related protein gene 2 (SFRP2),hyperplastic polyposis protein gene (HPP1) and O~6-methylguanine-DNA methyhransferase gene (MGMT) in feces for screening colorectal cancer (CRC).Methods Total DNA was isolated from fecal samples of 52 patients with colorectal cancer and 35 patients with benign colorectal diseases and 24 normal volunteers,and the methylation status of SFRP2,HPP1 and MGMT was analyzed with methylation-specific polymerase chain reaction.Results SFRP2,HPP1 and MGMT were methylated in 94.2%,71.2%,48.1% of CRCs,respectively.At least one of the three genes was methylated in 96.2% of CRCs and 81.8% of precancerous lesions,respectively.In contrast,of the 24 normal controls,only one had methylated SFRP2.These results indicated 93.7% sensitivity,77.1% specificity,84.3% positive predicative value and 90.2% negative predictive value of the test for detecting CRC and precancerous lesions.Conclusions Methylation analysis of SFRP2,HPP1 and MGMT gene in stool is a high sensitive screening tool for CRC and precancerous lesions.Analysis of fecal DNA methylation is expected to serve as a new detection way for CRC or a new screening tool for individuals at risk of developing colorectal neoplasm.