Risk factors for colorectal neoplasia in inflammatory bowel disease: a nested case-control study from Copenhagen county, Denmark and Olmsted county, Minnesota

Am J Gastroenterol. 2007 Apr;102(4):829-36. doi: 10.1111/j.1572-0241.2007.01070.x. Epub 2007 Jan 11.


Objectives: Population-based data on risk factors and protective factors for colorectal dysplasia and cancer in patients with inflammatory bowel disease (IBD) are sparse. We conducted a nested case-control study of such factors in two well-described IBD cohorts from Copenhagen County, Denmark and Olmsted County, Minnesota.

Methods: Forty-three neoplasia cases were matched on six criteria to 1-3 controls (N = 102). Medical records were scrutinized for demographic and clinical data. For each variable, the odds of neoplasia were estimated using conditional logistic regression.

Results: Primary sclerosing cholangitis (PSC) (odds ratio [OR] 6.9, 95% confidence interval [CI] 1.2-40), percentage of disease course with clinically active disease (OR [per 5% increase] 1.2, 95% CI 0.996-1.4), and >or=1 yr of continuous symptoms (OR 3.2, 95% CI 1.2-8.6) were associated with neoplasia, whereas a borderline association with median number of small-bowel x-rays (OR 1.3, 95% CI 0.96-1.6) was observed. We did not observe a protective effect of frequency of physician visits (OR 1.4, 95% CI 0.96-2.0), number of colonoscopies (OR 1.4, 95% CI 1.0-2.1), cumulative dose of sulfasalazine (OR [per 1,000 g] 1.1, 95% CI 1.0-1.3) and mesalamine (OR [per 1,000 g] 1.3, 95% CI 0.9-1.9), or partial intestinal resections (OR 1.5, 95% CI 0.3-7.1).

Conclusions: Subgroups of IBD patients-those with PSC, severe long-standing disease, and exposure to x-ray-were at greater risk of colorectal neoplasia. The protective effect of close follow-up, colonoscopy, and treatment with 5-aminosalicylates was questionable.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Case-Control Studies
  • Colonoscopy
  • Colorectal Neoplasms / epidemiology*
  • Colorectal Neoplasms / etiology
  • Denmark / epidemiology
  • Female
  • Gastrointestinal Agents / therapeutic use
  • Humans
  • Inflammatory Bowel Diseases / complications
  • Inflammatory Bowel Diseases / epidemiology*
  • Logistic Models
  • Male
  • Mesalamine / therapeutic use
  • Minnesota / epidemiology
  • Population Surveillance
  • Precancerous Conditions / epidemiology
  • Prognosis
  • Risk Factors
  • Sulfasalazine / therapeutic use


  • Gastrointestinal Agents
  • Sulfasalazine
  • Mesalamine