title: Association of the metformin with the risk of lung cancer: a meta-analysis.
abstract: OBJECTIVE
  To assess the correlation between metformin and risk of developing lung cancer by meta-analysis.
  
  
  METHODS
  Papers on the correlation between metformin and risk of lung cancer were searched from PubMed, MEDLINE, EMBASE, ISI Web of Science, and Cochrane Library.
  
  
  RESULTS
  Six papers on case-control study were included in this study, involving 39,787 metformin users and 177,752 controls. Meta-analysis showed that the risk of developing lung cancer was lower in metformin users than in those without metformin (OR=0.55, 95% CI: 0.35-0.85, P<0.001).
  
  
  CONCLUSIONS
  The risk of developing lung cancer is lower in metformin users than in those without metformin.
authors: Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P. R. China.
authors: Li
authors: L
authors: Wang
authors: Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P. R. China.
authors: Yong
authors: Y
authors: Song
authors: Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P. R. China.
authors: Guan-Nan
authors: GN
authors: Wu
authors: Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing 210002, P. R. China.
authors: Dong-Mei
authors: DM
authors: Yuan
keywords: Metformin; lung cancer; meta-analysis