title: Meta-analysis of the associations between TNF-α or IL-6 gene polymorphisms and susceptibility to lung cancer.
abstract: BACKGROUND
  Several studies have indicated an association between tumor necrosis factor-alpha (TNF-α) or interleukin (IL)-6 gene polymorphisms and lung cancer risk. However, the conclusions remain controversial.
  
  
  METHODS
  An English literature screening about case-control trials with regard to TNF-α (-308G/A) or IL-6 (174G/C) polymorphisms and lung cancer susceptibility was performed on PubMed, EMBASE, and EBSCO until November 2012. The pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated using STATA 11.0. Sensitivity analysis was performed by sequential omission of individual studies. Publication bias was evaluated by Egger's linear regression test and funnel plots.
  
  
  RESULTS
  Eight eligible studies, including 1,690 patients and 1,974 controls, were identified in this meta-analysis. Compared with the control, no significant association was revealed between TNF-α-308G/A (GG + GC vs. CC: OR = 1.10, 95% CI: 0.73 to 1.64; GG vs. GC + CC: OR = 1.02, 95% CI: 0.81 to 1.27; GC vs. CC: OR = 1.13, 95% CI: 0.73 to 1.77; GG vs. CC: OR = 1.04, 95% CI: 0.80 to 1.36; G vs. C: OR = 1.03, 95% CI: 0.90 to 1.18) or IL-6 174G/C (GG + GC vs. CC: OR = 1.10, 95% CI: 0.73 to 1.64; GG vs. GC + CC: OR = 1.02, 95% CI: 0.81 to 1.27; GC vs. CC: OR = 1.13, 95% CI: 0.73 to 1.77; GG vs. CC: OR = 1.04, 95% CI: 0.80 to 1.36; G vs. C: OR = 1.03, 95% CI: 0.90 to 1.18) and lung cancer risk. The pooled OR remained unchanged after removing the maximum-weight study and no publication bias was observed.
  
  
  CONCLUSIONS
  The study raises the possibility of no correlation between the polymorphisms of the two genes and lung cancer susceptibility. However, further researches with large-sample or subgroup analyses are necessary to validate the conclusions.
authors.affiliation: Department of Respiration, General Hospital of Ningxia Medical University, Shengli Street, Yinchuan, 750004, China. zhouweieiie@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Respiration, General Hospital of Ningxia Medical University, Shengli Street, Yinchuan, 750004, China. YanyanSong111@163.com.
authors.forename: Shuxiang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Respiration, General Hospital of Ningxia Medical University, Shengli Street, Yinchuan, 750004, China. XiaohongFan111@163.com.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Respiration, General Hospital of Ningxia Medical University, Shengli Street, Yinchuan, 750004, China. RunboZhong111@163.com.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Na
authors.affiliation: Department of Respiration, General Hospital of Ningxia Medical University, Shengli Street, Yinchuan, 750004, China. WeiZhang333@163.com.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.affiliation: Department of Respiration, General Hospital of Ningxia Medical University, Shengli Street, Yinchuan, 750004, China. XiaoxiaoGe444@163.com.
authors.forename: Xuan
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Respiration, General Hospital of Ningxia Medical University, Shengli Street, Yinchuan, 750004, China. LiyanJiang111@hotmail.com.
authors.forename: Lizhi
authors.initials: L
authors.lastname: Yuan
authors.affiliation: Department of Respiration, General Hospital of Ningxia Medical University, Shengli Street, Yinchuan, 750004, China. fzhenmengg@163.com.
authors.forename: Fanzhen
authors.initials: F
authors.lastname: Meng
mesh_terms: D016022:Case-Control Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008175:Lung Neoplasms / Q000235:genetics*; D011110:Polymorphism, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha