Crohn's disease and cancer risk (Denmark)

Objectives: The large number of studies of intestinal cancer among patients with Crohn's disease have provided inconsistent risk estimates in regard t o risk of both colorectal and small intestinal cancer. We investigated inci dence of cancer among Crohn's disease patients in comparison with the incid ence in the general population of Denmark. Methods: From the Danish National Registry of Patients we identified 2645 p atients who had been hospitalized with Crohn's disease during 1977-1989. Ca ncer incidence for up to 17 years was determined in the cohort and compared to an expected number derived from national cancer incidence rates. Results: The 15 observed cases of colorectal cancer were close to the expec ted number of 13.1 (SIR = 1.1; 95% CI 0.6-1.9), whereas the five cases of s mall intestinal cancer (three adenocarcinomas and two carcinoids) observed corresponded to an 18-fold increased risk (SIR = 17.9; 95% CI 5.8-42). Conclusions: A potential excess of colorectal cancer among subgroups of pat ients with Crohn's disease was not detectable in the overall risk estimate for colorectal cancer. Only for small intestinal cancer was a significantly elevated risk found among these patients hospitalized with Crohn's disease .