Objective: The objective of this study was to determine the risk of cancers in cohorts of patients with ulcerative colitis, Crohn's disease, or coeliac disease, compared with the risk in a control cohort.
Method: The method used was the analysis of a linked statistical database of hospital and mortality data in an area in southern England.
Results: Rate ratios for cancer (excluding cases occurring within the first year of follow-up), compared with the value of 1 in the control cohort, were 1.25 [95% confidence interval (CI), 1.13-1.39] in patients with ulcerative colitis, 1.27 (95% CI, 1.11-1.45) with Crohn's disease, and 1.16 (95% CI, 0.94-1.43) with coeliac disease. In patients with ulcerative colitis or Crohn's disease, there was a significantly high risk of cancer of the colon [2.22 (95% CI, 1.71-2.83) and 1.64 (95% CI, 1.09-2.39), respectively]. In patients with ulcerative colitis there was a significantly high risk of cancer of the rectum [1.84 (95% CI, 1.27-2.58)]. In patients with ulcerative colitis or Crohn's disease, who did not undergo partial or total colectomy for it, the rate ratios for colon cancer were, respectively, 5.52 (95% CI, 4.39-6.71) and 4.81 (95% CI, 3.52-6.47). In ulcerative colitis, there was an elevated risk of cancer of the rectum, liver and ovary. The rate ratio for lung cancer was low, but of borderline significance [0.72 (95% CI, 0.50-0.98)]. In Crohn's disease, the rate ratio was high for cancer of the cervix [2.63 (95% CI, 1.12-5.29)]. In patients with coeliac disease, the high-risk cancer was non-Hodgkin's lymphoma [rate ratio 3.28 (95% CI, 1.49-6.28)].
Conclusion: All three diseases carry an increased risk of cancer overall when the first year cases are included, though fairly modest in scale, and the increased risk seen in coeliac disease reduces when first year cases are excluded. Each has a distinctive pattern of individual high-risk cancers.