title: Nonsteroidal antiinflammatory drug use and lung cancer: a metaanalysis.
abstract: OBJECTIVE
  Studies done both in laboratory animals and humans suggest that nonsteroidal antiinflammatory drug (NSAID) use may reduce the risk of developing lung cancer. Many epidemiologic studies exploring this association lacked sufficient power to draw definitive conclusions. We conducted a metaanalysis to examine the effect of NSAID use on the risk of lung cancer.
  
  
  METHODS
  We searched the literature using MEDLINE, CANCERLIT, related conference abstracts, and bibliographies of selected studies. The estimators of relative risk (RR) and associated variances, adjusted for the greatest number of confounders, were abstracted and included in the metaanalysis. Combined estimators of RR were calculated using either fixed or random-effect models. Metaanalyses were performed on 14 studies (the number of cases ranged from 81 to 2,560) that examined the association between lung cancer and NSAIDs. Further, subgroup analyses were performed on the nine studies that had adjusted for the effects of smoking.
  
  
  RESULTS
  The combined estimate of RR was 0.79 (95% confidence interval [CI], 0.66 to 0.95) when all the studies were included in the analysis, and was 0.68 (95% CI, 0.55 to 0.85) when the analysis was limited to the subgroup of studies adjusted for smoking. The combined estimates for case-control studies and cohort studies within this subgroup were 0.63 (95% CI, 0.47 to 0.86) and 0.78 (95% CI, 0.62 to 0.98), respectively. We also observed that small cell lung cancer was more inversely associated with NSAID use (RR, 0.48; 95% CI, 0.30 to 0.75) than non-small cell lung cancer (RR, 0.66; 95% CI, 0.56 to 0.79).
  
  
  CONCLUSIONS
  The findings of this study support an inverse association between NSAID use and risk of lung cancer, but do not suggest a causal relationship.
authors.affiliation: Department of Medicine, Medical College of Ohio, 3120 Glendale Ave, Toledo, OH 43614-5809. skhuder@mco.edu.
authors.forename: Sadik A
authors.initials: SA
authors.lastname: Khuder
authors.forename: Nabeel A
authors.initials: NA
authors.lastname: Herial
authors.forename: Anand B
authors.initials: AB
authors.lastname: Mutgi
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Federman
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008175:Lung Neoplasms / Q000517:prevention & control*; D012306:Risk
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal