title: Risk factors for colorectal cancer in patients with ulcerative colitis: a case-control study.
abstract: OBJECTIVE
  The risk of colorectal cancer increases in patients with ulcerative colitis, most markedly among young patients and/or those with extensive disease at onset. However, it is unknown whether individual risk can be predicted more precisely and whether cancer risk can be reduced by long-term treatment with sulfasalazine.
  
  
  METHODS
  In a population-based cohort of 3112 patients with ulcerative colitis, we compared 102 cases of colorectal cancer and 196 matched controls without cancer. Hospital records were used to abstract information on pharmacological therapy, disease activity, and extraintestinal manifestations. The relative risk (RR) of cancer was estimated by conditional logistic regression.
  
  
  RESULTS
  Pharmacological therapy, especially sulfasalazine, lasting at least 3 months was associated with a significant protective effect (RR, 0.38; 95% confidence interval [CI], 0.20-0.69) independent of disease activity. There was also a tendency to an independent protective effect for cigarette smoking (RR, 0.15; 95% CI, 0.02-1.25) and higher disease activity (RR, 0.80; 95% CI, 0.49-1.33).
  
  
  CONCLUSIONS
  The risk of colorectal cancer among patients with ulcerative colitis can be reduced through pharmacological therapy. This finding is consistent with the reports of a protective effect of aspirin among individuals in the general population.
authors.affiliation: Cancer Epidemiology Unit, University Hospital, Uppsala, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Pinczowski
authors.forename: A
authors.initials: A
authors.lastname: Ekbom
authors.forename: J
authors.initials: J
authors.lastname: Baron
authors.forename: J
authors.initials: J
authors.lastname: Yuen
authors.forename: H O
authors.initials: HO
authors.lastname: Adami
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000150:complications* / Q000188:drug therapy; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D012460:Sulfasalazine / Q000009:adverse effects / Q000627:therapeutic use; D013548:Sweden / Q000453:epidemiology
chemical_list: D012460:Sulfasalazine