title: Increased risk for nonmelanoma skin cancers in patients who receive thiopurines for inflammatory bowel disease.
abstract: OBJECTIVE
  Patients with inflammatory bowel disease (IBD) who have been exposed to thiopurines might have an increased risk of skin cancer. We assessed this risk among patients in France.
  
  
  METHODS
  We performed a prospective observational cohort study of 19,486 patients with IBD, enrolled from May 2004 to June 2005, who were followed up until December 31, 2007. The incidence of nonmelanoma skin cancer (NMSC) in the general population, used for reference, was determined from the French Network of Cancer Registries.
  
  
  RESULTS
  Before the age of 50 years, the crude incidence rates of NMSC among patients currently receiving or who previously received thiopurines were 0.66/1000 and 0.38/1000 patient-years, respectively; these values were 2.59/1000 and 1.96/1000 patient-years for the age group of 50 to 65 years and 4.04/1000 and 5.70/1000 patient-years for patients older than 65 years. Among patients who had never received thiopurines, the incidence of NMSC was zero before the age of 50 years, 0.60/1000 for the ages of 50 to 65 years, and 0.84/1000 for those older than 65 years. A multivariate Cox regression model stratified by propensity score quintiles showed that ongoing thiopurine treatment (hazard ratio [HR], 5.9; 95% confidence interval [CI], 2.1-16.4; P = .0006) and past thiopurine exposure (HR, 3.9; 95% CI, 1.3-12.1; P = .02) were risk factors for NMSC. They also identified age per 1-year increase as a risk factor for NMSC (HR, 1.08; 95% CI, 1.05-1.11; P < .0001).
  
  
  CONCLUSIONS
  Ongoing and past exposure to thiopurines significantly increases the risk of NMSC in patients with IBD, even before the age of 50 years. These patients should be protected against UV radiation and receive lifelong dermatologic screening.
authors.affiliation: INSERM Unité 954 and Department of Gastroenterology, University Hospital of Nancy, Henri Poincaré University, Vandœuvre-lès-Nancy, France. peyrinbiroulet@gmail.com
authors.forename: Laurent
authors.initials: L
authors.lastname: Peyrin-Biroulet
authors.forename: Kiarash
authors.initials: K
authors.lastname: Khosrotehrani
authors.forename: Fabrice
authors.initials: F
authors.lastname: Carrat
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Bouvier
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Chevaux
authors.forename: Tabassome
authors.initials: T
authors.lastname: Simon
authors.forename: Frank
authors.initials: F
authors.lastname: Carbonnel
authors.forename: Jean-Frédéric
authors.initials: JF
authors.lastname: Colombel
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Dupas
authors.forename: Philippe
authors.initials: P
authors.lastname: Godeberge
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Hugot
authors.forename: Marc
authors.initials: M
authors.lastname: Lémann
authors.forename: Stéphane
authors.initials: S
authors.lastname: Nahon
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Sabaté
authors.forename: Gilbert
authors.initials: G
authors.lastname: Tucat
authors.forename: Laurent
authors.initials: L
authors.lastname: Beaugerie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000453:epidemiology*; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005602:France; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D015994:Incidence; D015212:Inflammatory Bowel Diseases / Q000150:complications* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011687:Purines / Q000009:adverse effects / Q000627:therapeutic use*; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology*; D013473:Sunscreening Agents / Q000627:therapeutic use; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D007166:Immunosuppressive Agents; D011687:Purines; D013473:Sunscreening Agents