Cancer in inflammatory bowel disease

The first case of cancer in inflammatory bowel disease (IBD) was reported a t The Mount Sinai Hospital in 1925 in a patient with ulcerative colitis (UC ). In 1956, carcinoma of the jejunum was described in a patient with region al enteritis (Crohn's disease [CD]). IBD cancers are preceded by dysplasia, and the relative risk increases with duration of the IBD. CD cancers are m ore proximally distributed than are UC cancers. Both tend to occur at the s ite of the overt disease and both develop at earlier ages (47 UC, 50 CD) th an in the de novo colorectal cancer (70 years). The absolute cumulative colon cancer frequencies (8% UC, 7% CD) are identic al after 20 years, emphasizing the importance of regular surveillance in bo th types of IBD. Moreover, the increased risk of colon cancer exists in pat ients with CD even when CD is confined to the small bowel, and patients wit h IBD have increased risks of developing extraintestinal and reticuloendoth elial tumors in both CD and UC, as well as ano-vulval and malignant melanom a in CD. Colitic colorectal cancers are often diffuse, extensive, multiple and right-sided with insidious presentation. The prognosis is no worse afte r operation than that of de novo colon cancer. Most small bowel cancers in CD are adenocarcinomas, rather than sarcomas, a nd present at a younger age, more diffusely and more distally than de novo cancers, usually making them undiagnosable at a curable early stage; indeed , two-thirds present with intestinal obstruction. Strictures of the colon a re common in patients with IBD, and they have a 10-fold risk for colon canc er, 30-fold for UC, and 6-fold for CD. The risk increases with disease dura tion. The indications for surgery are absolute, relative and incidental, an d the procedures include segmental resection, total proctocolectomy, subtot al colectomy and palliative procedures.