[Tracing colorectal carcinoma in patients with inflammatory bowel disease].

In patients with ulcerative colitis the risk of colorectal cancer is increased. Based on a number of studies, British and American guidelines support endoscopic surveillance in these patients. As the cancer risk in ulcerative colitis increases with disease duration, it is recommended that surveillance is started 8-20 years after diagnosis depending on the extent of disease. Although previous studies have shown that the observed cancer risk in colonic Crohn's disease is unrelated to duration of disease, similar surveillance of these patients is suggested. A substantial number of cases of carcinoma in patients with inflammatory bowel disease present before scheduled onset of surveillance. Therefore, the optimal time of onset of surveillance is disputable. However, taking into account the relatively low risk of colorectal cancer in the early stages of inflammatory bowel disease, it will be hard to achieve an acceptable risk-benefit ratio of extending surveillance by starting surveillance colonoscopies at a younger age.