Cancer Risk in Inflammatory Bowel Disease: Over- or Underrated?

Cancer Risk in Inflammatory Bowel Disease: Over-or Underrated? Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). It is accepted that the risk increases with longer duration of colitis, greater anatomic extent of colitis, the presence of primary sclerosing cholangitis, family history of CRC, and degree of inflammation of the bowel. Some groups have described in early studies a cumulative probability as high as 60% for developing cancer after 40 years of disease. However, these center-based studies often overestimate the risk. Population-based studies describe that risk for CRC among patients with both ulcerative colitis and Crohn's colitis is approximately 2- to 3-fold greater than that of the general population. The reasons may be the more widespread use of surveillance colonoscopy, a chemoprotective effect attributable to the more widespread use of 5-ASA therapies, and more aggressive surgical intervention. However, new epidemiological studies demonstrated that colonoscopic surveillance strategies based on disease duration delayed or missed the detection of early CRC in a substantial number of patients. Therefore, the risk in early extended IBD is underestimated.