Methylation pattern of SFRP1 promoter in stool sample is a potential marker for early detection of colorectal cancer

BACKGROUND: To setup a non-invasive genetic screening method for colorectal cancer, we evaluated the promoter methylation status of secreted frizzled-related protein1 (sfrp1) in stool samples of colorectal cancer with respect to a series of healthy individuals, using methylation-specific polymerase chain reaction. MATERIALS AND METHODS: In stool samples from 25 patients with colorectal cancer and 25 healthy control subjects, isolated DNA was treated with sodium bisulfite and analyzed by methylation-specific polymerase chain reaction with primers specific for methylated or unmethylated promoter sequences of the SFRP1 gene. RESULT: Methylation of the SFRP1 promoter was present in the stool DNA of patients with colorectal cancer. A sensitivity of 52% and specificity of 92% were achieved in the detection of colorectal neoplasia. The difference in methylation status of the SFRP1 promoter between the patients with colorectal neoplasia and the control group was statistically highly significant (P = 0.006). CONCLUSIONS: The results indicate that this DNA stool test of methylation of the SFRP1 promoter is a sensitive and specific method. It is assumed that the test is potentially useful for the early detection of colorectal cancer.