title: The interleukin-6 -174G/C polymorphism and prostate cancer risk: a systematic review and meta-analysis.
abstract: OBJECTIVE
  This systematic review and meta-analysis was undertaken to integrate previous findings and summarize the effect size of the association of interleukin-6 (IL-6) genetic polymorphism -174G/C with susceptibility to prostate cancer (PCa).
  
  
  METHODS
  All eligible studies of IL-6 -174G/C polymorphism and PCa risk were collected from the following electronic databases: PubMed and the Cochrane Library, with the last report up to June 1, 2011. Statistical analyses were performed by Review Manage version 5.0 and Stata 10.0.
  
  
  RESULTS
  A total of 7 independent studies, including 9,959 cases and 12,361 controls, were identified. When all studies were pooled, we did not detect a significant association of -174G/C polymorphism with PCa risk. When stratifying for race, similar results were obtained; evidence of a significant relation was absent in both Caucasians and the mixed population. After stratifying the studies by study types, -174G/C polymorphism was significantly associated with PCa risk when examining the contrast of CC + GC versus GG (OR = 1.44, 95% CI = 1.05-1.98, p = 0.03) in cohort studies but not in case-control studies.
  
  
  CONCLUSIONS
  Our review suggest that -174G/C polymorphism is associated with an increased PCa risk in two cohort studies from one article. Additional well-designed studies are warranted to validate these findings.
authors.affiliation: Department of Urology, Second Hospital of Tianjin Medical University, Tianjin Institute of Urology, Tianjin, PR China.
authors.forename: Hongtuan
authors.initials: H
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.forename: Ranlu
authors.initials: R
authors.lastname: Liu
authors.forename: Baojie
authors.initials: B
authors.lastname: Ma
mesh_terms: D016009:Chi-Square Distribution; D020022:Genetic Predisposition to Disease; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D016014:Linear Models; D008297:Male; D016017:Odds Ratio; D010641:Phenotype; D011110:Polymorphism, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000276:immunology; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6