Malignancies in inflammatory bowel disease: fact or fiction?

Abstract

Background: The association between ulcerative colitis (UC), Crohn disease (CD) and colorectal cancer (CRC) has been confirmed in several studies. The aim of this study was critical analysis of the relation between IBD and malignancy.

Methods: Review of the literature.

Results: In UC, the extent of the disease, its duration and start at a young age are risk factors for the development of CRC. Primary sclerosing cholangitis and colonic strictures are additional risk factors for development of CRC. The relation between azathioprine or 6-MP and the development of lymphomas is a subject of debate. The administration of anti-TNF-alpha has produced some concern about the development of lymphomas in CD. However, at present there is no evidence of lymphomas caused by anti-TNF-alpha in CD. On the contrary, some drugs seem to have a preventive effect on CRC development in UC. 5-aminosalicylic acid in particular and to a lesser extent sulphasalazine have prevented the development of CRC significantly in retrospective studies. In CD, there is no strong relationship between the disease and the development of CRC or other malignancies. Only the development of small-bowel carcinoma is reported with a much higher frequency.

Conclusions: There is a correlation with UC and the development of CRC. For CD, this correlation is less firmly established. There is a possible, but not proven, relation between AZA/6-MP use and the development of lymphoma in IBD. There is also a probable relationship between CD and the development of small-bowel carcinoma. In some retrospective studies, the use of 5-aminosalicylic or sulphasalazine has been shown to prevent the development of CRC in UC.