title: Alcohol consumption and lung cancer risk in never smokers: a meta-analysis.
abstract: BACKGROUND
  The role of alcohol consumption as an independent risk factor for lung cancer is controversial. Since drinking and smoking are strongly associated, residual confounding by smoking may bias the estimation of alcohol consumption and lung cancer risk relation. Therefore, we undertook a meta-analysis to quantitatively assess the association between alcohol and risk of lung cancer in never smokers.
  
  
  METHODS
  After a literature search in Medline, we included all case-control and cohort studies published up to January 2010 that reported an estimate of the association between alcohol intake and lung cancer risk in never smokers.
  
  
  RESULTS
  We selected 10 articles, including 1913 never smoker lung cancer cases. The random-effects pooled relative risk (RR) for drinkers versus nondrinkers was 1.21 [95% confidence interval (CI) 0.95-1.55]. The same figure was 1.05 (95% CI 0.89-1.23) after the exclusion of one outlier study. At the dose-response analysis, RR for an increase in alcohol intake of 10 g/day was 1.01 (95% CI 0.92-1.10).
  
  
  CONCLUSIONS
  Alcohol consumption was not associated with lung cancer risk in never smokers. Even if the synergistic effect of smoking and alcohol cannot be ruled out, our results suggest that alcohol does not play an independent role in lung cancer etiology.
authors.affiliation: Department of Statistics, University of Milan-Bicocca, Milan; Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan. Electronic address: vincenzo.bagnardi@ieo.it.
authors.forename: V
authors.initials: V
authors.lastname: Bagnardi
authors.affiliation: Department of Statistics, University of Milan-Bicocca, Milan; Department of Clinical Medicine and Prevention, Centre of Biostatistics for Clinical Epidemiology, University of Milan-Bicocca, Monza.
authors.forename: M
authors.initials: M
authors.lastname: Rota
authors.affiliation: Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan; Institute of Medical Statistics and Biometrics 'G. A. Maccacaro', University of Milan, Milan, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Botteri
authors.affiliation: Department of Statistics, University of Milan-Bicocca, Milan.
authors.forename: L
authors.initials: L
authors.lastname: Scotti
authors.affiliation: International Agency for Research on Cancer, Lyon, France.
authors.forename: M
authors.initials: M
authors.lastname: Jenab
authors.affiliation: Department of Statistics, University of Milan-Bicocca, Milan; Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Bellocco
authors.affiliation: Mario Negri Institute for Pharmacological Research, Milan, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Tramacere
authors.affiliation: Mario Negri Institute for Pharmacological Research, Milan, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Pelucchi
authors.affiliation: Mario Negri Institute for Pharmacological Research, Milan, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Negri
authors.affiliation: Institute of Medical Statistics and Biometrics 'G. A. Maccacaro', University of Milan, Milan, Italy; Mario Negri Institute for Pharmacological Research, Milan, Italy.
authors.forename: C
authors.initials: C
authors.lastname: La Vecchia
authors.affiliation: Department of Statistics, University of Milan-Bicocca, Milan.
authors.forename: G
authors.initials: G
authors.lastname: Corrao
authors.affiliation: The Tisch Cancer Institute, Mount Sinai School of Medicine, New York, USA; International Prevention Research Institute, Lyon, France.
authors.forename: P
authors.initials: P
authors.lastname: Boffetta
mesh_terms: D000428:Alcohol Drinking / Q000009:adverse effects*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000209:etiology*; D008297:Male; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*