Cancer in Inflammatory Bowel Disease

Colorectal cancer (CRC) is a complication in both patients with longstanding ulcerative colitis and those with Crohn's disease. As with sporadic CRC, surgical therapy (with adjuvant chemotherapy in advanced disease) is the only effective treatment. Identifying risk factors for CRC in inflammatory bowel disease (IBD) should allow patients to receive appropriate medical, endoscopic, and surgical care to minimize CRC morbidity and mortality. Total proctocolectomy remains the most effective form of cancer prophylaxis in IBD patients, but because of the impact of this approach and the low absolute risk of cancer, clinicians seldom recommend it. Colonoscopic surveillance with systematic biopsies is used to detect mucosal dysplasia and thus identify those patients at greatest risk for developing CRC. Patients with dysplasia other than that in readily excised polyps should be referred for surgery. Although fraught with limitations, surveillance is the best method currently available for reducing CRC mortality and morbidity short of prophylactic colectomy. It will have to remain the standard of practice until better diagnostic tests are available. Surveillance should be offered and performed in the same manner for patients with Crohn's disease and ulcerative colitis. Chemoprevention may prove effective in the future, but currently used agents have only a modest benefit, if any. Adenocarcinoma of the small intestine occurs at an increased rate in patients with Crohn's disease of the bowel with longstanding small bowel involvement, but there are no current methods of early detection. Treatment is based on disease identified from evaluation of symptoms or incidental finding. Some extraintestinal cancers have been noted to occur at increased rates in series from referral centers but not in population-based studies.