title: Inhaled corticosteroids and risk of lung cancer among COPD patients who quit smoking.
abstract: OBJECTIVE
  COPD is associated with an increased risk of lung cancer. We examined whether inhaled corticosteroids (ICS) used concomitantly with long-acting beta(2)-agonists (LABA) were associated with reduction in lung cancer risk in COPD patients.
  
  
  METHODS
  We conducted a retrospective cohort study of patients with a first-time diagnosis of COPD (index date) between 1989 and 2003 who were initially free of lung cancer, had quit smoking, were aged >or=50 years at time of diagnosis, and were regular users of ICS, ICS/LABA concomitantly, or short-acting bronchodilators (SABD). A nested case-control design was applied to overcome the time-varying nature of treatment.
  
  
  RESULTS
  We identified 7079 COPD patients who were regular users of the therapies of interest, of whom 127 subsequently had lung cancer and were matched to 1470 controls of same gender and age. Lung cancer was diagnosed in 6.0% of concomitant ICS/LABA users compared with 7.3% of ICS and 10.9% of SABD users. In multivariate analyses, reductions in lung cancer risk were observed, with hazard ratio (HR) 0.50 (95% confidence interval, 0.27-0.90) in ICS/LABA users and 0.64 (0.42-0.98) in ICS users, compared with SABD users. In assessing 'dose-response' relationships, we found risk reductions: HR of 0.75 (0.33-1.75) and 0.39 (0.19-0.79) in ICS/LABA users with 1-2 and 3+ prescriptions/year, respectively, and 0.88 (0.51-1.52) and 0.51 (0.30-0.84) in ICS users with 1-2 and 3+ prescriptions/year, respectively.
  
  
  CONCLUSIONS
  Regular use of ICS, with and without LABA, may reduce the risk of lung cancer among former smokers with diagnosed COPD.
authors.affiliation: Worldwide Epidemiology, GlaxoSmithKline R&D, Greenford, UK. victor.kiri@parexel.com
authors.forename: Victor A
authors.initials: VA
authors.lastname: Kiri
authors.forename: Leonardo M
authors.initials: LM
authors.lastname: Fabbri
authors.forename: Kourtney J
authors.initials: KJ
authors.lastname: Davis
authors.forename: Joan B
authors.initials: JB
authors.lastname: Soriano
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage* / Q000627:therapeutic use; D000318:Adrenergic beta-Agonists / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000150:complications / Q000188:drug therapy; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002318:Cardiovascular Diseases / Q000150:complications; D016022:Case-Control Studies; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008175:Lung Neoplasms / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control; D008297:Male; D001523:Mental Disorders / Q000150:complications; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D012189:Retrospective Studies; D012306:Risk; D016540:Smoking Cessation
chemical_list: D000305:Adrenal Cortex Hormones; D000318:Adrenergic beta-Agonists; D001993:Bronchodilator Agents