Purpose: The aims of this study were to investigate the use of quantitative CGI methylation data from stool DNA to classify colon cancer patients and to relate stool CGI methylation levels to those found in corresponding tissue samples.
Methods: We applied a quantitative methylation-specific PCR assay to determine CGI methylation levels of six genes, previously shown to be aberrantly methylated during colorectal carcinogenesis. Assays were performed on DNA from biopsies of "normal" mucosa and stool samples from 57 patients classified as disease-free, adenoma, or cancer by endoscopy, and in tumour tissue from cancer patients.