title: Chronic statin therapy and the risk of colorectal cancer.
abstract: OBJECTIVE
  Epidemiologic studies on a potential chemopreventive effect of statin therapy have yielded conflicting results. We sought to clarify whether long-term statin therapy has a chemopreventive effect on the risk of colorectal cancer (CRC) in a large, population-representative cohort.
  
  
  METHODS
  A nested case-control study was conducted among patients > or =50 years of age and with > or =5 years of CRC-free initial follow-up in the General Practice Research Database (GPRD; 1987-2002). Cases consisted of all patients with incident CRC. Up to 10 controls were matched with each case on practice site and both duration and calendar time of follow-up prior to the index date. The primary exposure of interest was > or =5 years of cumulative statin use.
  
  
  RESULTS
  We identified 4432 incident CRC cases and 44 292 controls. The adjusted odds ratio (OR) for > or =5 years of statin exposure was 1.1 (95% confidence interval (CI): 0.5-2.2). Chronic NSAID/aspirin use did not modify this primary association (test for interaction, p = 0.5). Compared to statin non-users, the adjusted OR for 10 years of statin exposure was 1.3 (95% CI: 0.6-2.7), and the adjusted OR associated with the highest quartile of cumulative statin dose was 1.2 (95% CI: 0.9-1.7). There was a non-statistically significant trend towards a possible reduction in CRC risk among users of high daily statin dose.
  
  
  CONCLUSIONS
  Long-term statin therapy at usual doses was not associated with a significantly reduced risk of CRC. A chemopreventive effect at high daily doses cannot be excluded.
authors.affiliation: Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA 19104-6021, USA. yangy@mail.med.upenn.edu
authors.forename: Yu-Xiao
authors.initials: YX
authors.lastname: Yang
authors.forename: Sean
authors.initials: S
authors.lastname: Hennessy
authors.forename: Kathleen
authors.initials: K
authors.lastname: Propert
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Hwang
authors.forename: Monika
authors.initials: M
authors.lastname: Sarkar
authors.forename: James D
authors.initials: JD
authors.lastname: Lewis
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013995:Time
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors