title: Long-term risk of cancer in ulcerative colitis: a population-based cohort study from Copenhagen County.
abstract: OBJECTIVE
  Ulcerative colitis (UC) is associated with an increased risk for colorectal cancer (CRC) and possibly also increased risk for cancers outside the intestinal tract. We followed-up a population-based cohort of 1160 patients with UC diagnosed in Copenhagen County between 1962 and 1987 for up to 36 years to analyze the overall and site-specific cancer risk.
  
  
  METHODS
  Observed vs. expected cancers were presented as standardized morbidity ratio (SMR) with 95% exact confidence intervals (CI) calculated by using individual person-years at risk and sex- and age-specific incidence rates for the Danish background population in 1995.
  
  
  RESULTS
  The cohort was followed-up for a median of 19 years, or 22,290 person-years. A total of 124 malignancies were observed compared with 139.85 expected (SMR, .89; 95% CI, .74-1.07). The observed number of CRCs was almost exactly equal to expected: 13 cases vs. 12.42 (SMR, 1.05; 95% CI, .56-1.79). The cumulative probability of CRC was .4% by 10 years, 1.1% by 20 years, and 2.1% by 30 years of disease. Among men, melanoma was increased (SMR, 3.45; 95% CI, 1.38-7.10); otherwise, no increased risk for cancer could be detected. No hepatobiliary cancers and no increased risk for lymphoma or leukemia were found.
  
  
  CONCLUSIONS
  Neither the overall cancer risk, nor the CRC risk, were increased in this population-based cohort after a median of 19 years of follow-up evaluation. An active surgical approach in medical treatment failures and long-term use of 5-aminosalicylic acid (5-ASA) as relapse prevention may explain this remarkable result.
authors.affiliation: Herlev Hospital, University of Copenhagen, Department of Medical Gastroenterology C, Herlev 2730, Denmark. Kawi@herlevhosp.kbhamt.dk
authors.forename: Karen V
authors.initials: KV
authors.lastname: Winther
authors.forename: Tine
authors.initials: T
authors.lastname: Jess
authors.forename: Ebbe
authors.initials: E
authors.lastname: Langholz
authors.forename: Pia
authors.initials: P
authors.lastname: Munkholm
authors.forename: Vibeke
authors.initials: V
authors.lastname: Binder
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001379:Azathioprine / Q000627:therapeutic use; D015331:Cohort Studies; D003082:Colectomy; D003093:Colitis, Ulcerative / Q000453:epidemiology* / Q000628:therapy; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008137:Longitudinal Studies; D008297:Male; D019804:Mesalamine / Q000627:therapeutic use; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D011159:Population Surveillance; D012042:Registries; D018570:Risk Assessment
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007166:Immunosuppressive Agents; D019804:Mesalamine; D001379:Azathioprine