Review article: the effect of aminosalicylates and immunomodulation on cancer risk in inflammatory bowel disease.

Ulcerative colitis and, maybe to a similar extent, Crohn's disease are associated with an increased risk of colorectal carcinoma. As a consequence of this increased risk, surveillance strategies have been proposed to prevent colorectal carcinoma through early detection of dysplasia, which may herald malignant disease. These surveillance strategies are controversial for several reasons discussed in this review. It may be concluded from the relevant studies that regular use of at least 1.2 g of mesalazine per day may effectively prevent about two out of three colon cancers in ulcerative colitis. In contrast, there seems to be no role for either mercaptopurine or folic acid in protection from colon cancer.