Colorectal cancer (CRC) originates in approximately one per cent of subjects with idiopathic bowel disease (IBD). Nevertheless, it participates on their mortality by 10–20 per cent.
IBD-associated CRC appears at an earlier age than sporadic CRC. IBD-associated CRC is accompanied by similar genetic markers as sporadic CRC, but their order and frequency are different.
IBD-associated cancer is frequently multifocal and more aggressive, The risk factors include: duration and extent of colitis, beginning of IBD at an early age and ongoing disease at a higher age (above 60 years), endoscopic and histological severity of inflammation, family history of sporadic CRC, and co- -existent primary sclerosing cholangitis. Prevention of IBD-associated CRC in long-standing disease requires a surveillance program.
Its main steps include: annual or biannual colonoscopies, four-quadrant biopsies obtained every 10 centimeters and finding of dysplasia (unequivocal malignant transformation of the epithelium without involvement of mucosal lamina propria). The confirmation of intraepithelial neoplasia requires surgery, Modern endoscopic techniques improve the detection of dysplastic lesions and enable to lower the number of biopsies.
Biomarkers of molecular genetics may improve future results of the surveillance program. treatment and prevention of dysplasia.