title: Risk factors for colorectal neoplasia in inflammatory bowel disease: a nested case-control study from Copenhagen county, Denmark and Olmsted county, Minnesota.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Medical Gastroenterology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Tine
authors.initials: T
authors.lastname: Jess
authors.forename: Edward V
authors.initials: EV
authors.lastname: Loftus
authors.forename: Fernando S
authors.initials: FS
authors.lastname: Velayos
authors.forename: Karen V
authors.initials: KV
authors.lastname: Winther
authors.forename: William J
authors.initials: WJ
authors.lastname: Tremaine
authors.forename: Alan R
authors.initials: AR
authors.lastname: Zinsmeister
authors.forename: W
authors.initials: W
authors.lastname: Scott Harmsen
authors.forename: Ebbe
authors.initials: E
authors.lastname: Langholz
authors.forename: Vibeke
authors.initials: V
authors.lastname: Binder
authors.forename: Pia
authors.initials: P
authors.lastname: Munkholm
authors.forename: William J
authors.initials: WJ
authors.lastname: Sandborn
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000209:etiology; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005765:Gastrointestinal Agents / Q000627:therapeutic use; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D019804:Mesalamine / Q000627:therapeutic use; D008910:Minnesota / Q000453:epidemiology; D011159:Population Surveillance; D011230:Precancerous Conditions / Q000453:epidemiology; D011379:Prognosis; D012307:Risk Factors; D012460:Sulfasalazine / Q000627:therapeutic use
chemical_list: D005765:Gastrointestinal Agents; D012460:Sulfasalazine; D019804:Mesalamine