title: Associations between RASSF1A promoter methylation and NSCLC: a meta-analysis of published data.
abstract: BACKGROUND
  RASSF1A has been reported to be a candidate tumor suppressor in non-small cell lung cancer (NSCLC). However, the association between RASSF1A promoter methylation and NSCLC remains unclear, particularly in regarding links to clinicopathologic features.
  
  
  METHODS
  Eligible studies were identified through searching PubMed, EMBASE, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases. Studies were pooled and odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated. Funnel plots were also performed to evaluate publication bias.
  
  
  RESULTS
  Nineteen studies involving 2,063 cases of NSCLC and 1,184 controls were included in this meta-analysis. A significant association was observed between RASSF1A methylation and NSCLC in the complete data set (OR = 19.42, 95% CI: 14.04- 26.85, P < 0.001). Pooling the control tissue subgroups (heterogeneous/autologous) gave pooled ORs of 32.4 (95% CI, 12.4-84.5) and 17.7 (95% CI, 12.5-25.0) respectively. Racial subgroup (Caucasian/Asian) analysis gave pooled ORs of 26.6 (95% CI, 10.9-64.9) and 20.9 (95% CI, 14.4-30.4) respectively. The OR for RASSF1A methylation in poorly-differentiated vs. moderately/well-differentiated NSCLC tissues was 1.88 (95% CI, 1.32- 2.68, P<0.001), whereas there were no significant differences in RASSF1A methylation in relation to gender, pathology, TNM stage and smoking behavior among NSCLC cases.
  
  
  CONCLUSIONS
  This meta-analysis suggests a significant association between RASSF1A methylation and NSCLC, confirming the role of RASSF1A as a tumor suppressor gene. Large-scale and well-designed case-control studies are needed to validate the associations identified in the present meta-analysis.
authors.affiliation: Department of Chemotherapy, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, China.
authors.forename: Wen-Jian
authors.initials: WJ
authors.lastname: Liu
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Tan
authors.forename: Bao-Ping
authors.initials: BP
authors.lastname: Guo
authors.forename: Qing
authors.initials: Q
authors.lastname: Ke
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
authors.forename: Hong
authors.initials: H
authors.lastname: Cen
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000473:pathology; D016022:Case-Control Studies; D019175:DNA Methylation; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D011379:Prognosis; D011401:Promoter Regions, Genetic / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins