Patterns of neoplasia in Crohn's disease and ulcerative colitis.

Cancer occurred in 28 of 579 patients (4.8%) with Crohn's disease (CD) and in 30 of 267 (11.2%) with ulcerative colitis (UC) admitted to the Mount Sinai Hospital between 1960--1976. The proportion of cancers that were extraintestinal was greater in CD than in UC (43 vs. 12%), as was the proportion of gastrointestinal cancers that arose in apparently normal bowels (33 vs. 4%). The incidence of gastrointestinal cancer increase with duration of disease in both CD and UC, but the absolute rates were three times higher in UC. For extraintestinal cancer, on the other hand, there was less correlation with increasing duration of disease, and no higher frequency in UC than in CD. Mortality from gastrointestinal cancer was 82% in CD and 50% in UC, but occurred only within two years of tumor diagnosis; survival beyond two years seemed to indicate a favorable prognosis.