Crohn’s Disease - CANCER

Posted by Alex

Cancer of the colon is a long-term complication of UC. Its development depends on two factors: the extent of mucosal involvement (pancolitis greater than left-sided colitis) and the duration of disease. Severity of the initial attack, subsequent course, and specific medical therapies are not related to the cancer risk. Colonic adenocarcinomas may occur in patients who have had quiescent UC for decades. Indeed, these may be the patients at highest risk. In Europe, where colectomy is performed earlier, the risk of cancer is reduced.

 
TABLE 104-2 - CANCER IN ULCERATIVE COLITISRisk factors
Extent of colon involved
Duration of disease after 10 years
Surveillance
Begin after 10 years
Increase frequency of surveillance with increased duration of disease
Warning
Indefinite dysplasia: requires follow-up 3-6 months and/or confirmation by experienced pathologist
Surgical indication
Confirmed dysplasia, or dysplasia-associated lesion or mass (DALM)

 

Mucosal dysplasia is a precursor of cancer. Dysplasia can be identified with colonoscopic biopsies by experienced pathologists and must be distinguished from inflammatory or regenerative epithelial changes. Repeat biopsies and aggressive medical therapy should be considered when pathologic interpretation is in doubt. Confirmed epithelial dysplasia is an indication for colectomy, as malignancies are often identified separate from the dysplastic foci. Routine screening for dysplasia and neoplasia is now recommended in longstanding UC. Surveillance colonoscopies and biopsies throughout the length of the colon should be initiated after 8 to 10 years of extensive colitis and repeated at 1- to 2-year intervals. The finding of dysplasia warrants confirmation by an experienced pathologist or repeat examination. Dysplasia in a nodular or polypoid lesion has an extremely high (> 50%) association with concurrent malignancy. Dysplasia and cancers in UC can occur in normal flat mucosa, with ulceration or stricture formation, or within a polyp or mass.

CD also increases the incidence of adenocarcinomas of the intestine. The same risk factors (extent and duration) probably apply but have not been as clearly established for CD. Patients with inactive CD should be monitored for a change in symptoms, bleeding, or obstruction; endoscopic or radiographic evaluation should be pursued for a change in an otherwise inactive phase. There is also a small increased risk of leukemia, lymphoma, and bile duct carcinomas in patients with IBD.