Intestinal cancer risk and mortality in patients with Crohn's disease.

BACKGROUND: It is important to know about mortality, risk of intestinal cancer, and surgical intervention as well as possible predictive factors for patients with Crohn's disease. These prognostic parameters were estimated by regular follow-up of a complete, regional incidence cohort of 373 patients.

METHODS: Annual assessments of clinical conditions were the basis for statistical evaluation with life table analysis, calculations of relative risk, and lifetime cancer risk.

RESULTS: Survival curves for the total group of patients with Crohn's disease and the background population did not differ. However, a subgroup of patients aged 20-29 years at diagnosis (P = 0.04) and a subgroup of patients with extensive small bowel disease (P = 0.03) showed slightly increased mortality within the first 5 years. Cancer in small and/or large bowel occurred in 3 patients vs. an expected 1.8(P = NS). Small bowel cancer was found in 2 patients vs. the 0.04 expected (P = 0.001). Lifetime risk of intestinal cancer was 4.1% compared with 3.8% for the Danish population in general (P = NS). Probability of surgical resection within 15 years after diagnosis was 70%. The initial extent of disease significantly influenced the probability for resection, which was 78% in ileocecal enteritis and 44% in all other localizations within 5 years after diagnosis.

CONCLUSIONS: The overall mortality and life-time risk of cancer in patients with Crohn's disease was not found increased, although the risk of rare small bowel cancer was significantly increased.