OBJECTIVETo study whether combined detection of the methylation status of vimentin, sFRP1, and HPP1 gene can increase the positive methylation rate in colorectal cancer.

METHODSTissue samples were collected from 90 patients with colorectal cancer, 60 patients with adenomatous polyp, and 20 healthy controls. DNA was extracted and the methylation status of vimentin, sFRP1, and HPP1 gene was detected by Methylation-specific PCR (MSP). The relationship between clinicopathologic features of colorectal cancer and gene methylation was analyzed.

RESULTSThe methylation rates of vimentin, sFRP1, and HPP1 were 66.7%, 68.9%, and 72.2% in colorectal cancer, 53.3%, 55.0%, and 50.0% in colorectal adenomas, and 0, 0, and 5.0% in healthy controls, respectively. The methylation of each of the three genes in colorectal cancer tissues was higher than colorectal adenomas and healthy controls(P<0.05). The diagnostic sensitivity by combining three methylation markers was 93.3% in colorectal cancer, 76.7% in colorectal adenomas, which was higher than the sensitivity using single gene testing(P<0.05). No significant associations existed between the methylation status of the three genes and clinical characteristics including sex, age, tumor location, lymph node metastases, distant metastasis, and TNM stage(P>0.05).

CONCLUSIONSDNA methylation levels of vimentin, sFRP1 and HPP1 are significantly higher in colorectal cancer tissue. Combined detection significantly improves the positive rate of methylation, and may be used as early diagnosis method for colorectal cancer.