Surveillance strategies in inflammatory bowel disease.

Patients with longstanding ulcerative colitis (UC) are at increased risk of developing colorectal cancer (CRC). Although data for CRC risk in Crohn's disease (CD) are limited, it has been suggested that the risk is comparable to UC. Current strategies for the prevention and early detection of cancer in this high risk population are based on the concept of an inflammation-neoplasia-carcinoma sequence. To reduce CRC mortality in inflammatory bowel disease (IBD), colonoscopic surveillance with random and targeted biopsies are recommended to detect early neoplasia. The introduction of novel endoscopic techniques such as conventional or virtual chromoendoscopy to facilitate targeted biopsies or confocal laser endomicroscopy to further characterise suspicious lesions has become increasingly associated with enhanced neoplasia detection. However, there is only indirect evidence that such surveillance strategies are likely to be effective in reducing the risk of death from IBD-associated CRC. Furthermore, new data suggests that surveillance strategies largely based upon disease duration are leading to delayed or missed diagnosis of early CRC in a substantial number of patients. Therefore, current surveillance guidelines seem to lack efficacy and need to be reassessed.