Mucosal biopsies from groups Normal (NOR) and patients who underwent curative large bowel resection for colorectal cancer (M-CRC)

The challenge of preventing colorectal cancer (CRC) is the early identification of individuals whose apparently normal colorectal mucosa will develop cancer, because of inherited trait or environmental exposure. We sought to use genome-wide expression profiling of endoscopic biopsies to detect a signature of propensity for cancer. We performed oligonucleotide microarray analysis of normal appearing mucosa of the following cases: healthy individuals (NOR), disease-free carriers predisposed to HNPCC (hereditary non-polyposis CRC), disease-free patients who underwent curative large bowel resection for CRC 1 to 15 years earlier and patients with CRC (MCRC) (GSE23011). As test set we run on affymetrix arrays an independent set of mucosal biopsies of MCRC and NOR samples. This profiling is based on the analysis of 5 patients who underwent curative large bowel resection for CRC from 1 to 15 years before (MCRC samples), and 12 endoscopy-negative, asymptomatic individuals (NOR samples)