title: Does CYP2E1 RsaI/PstI polymorphism confer head and neck carcinoma susceptibility?: A meta-analysis based on 43 studies.
abstract: BACKGROUND
  Previous reports showed that CYP2E1 RsaI/PstI polymorphism may be a risk factor for cancers. Published meta-analyses in 2010 and 2011, respectively, on the relationship of CYP2E1 RsaI/PstI polymorphisms with the susceptibility to head and neck carcinoma (HNC) have generated inconsistent results. Thus, this study aimed to conduct an updated meta-analysis involving published studies up to Nov 2015 to get a more confidential result.
  
  
  METHODS
  Eligible studies up to Nov 2015 were retrieved and screened. Data were extracted and a quantitative meta-analysis was conducted. Subgroup analyses on ethnicity, source of controls, sample size, genotyping method, smoking status, and drinking status were also performed.
  
  
  RESULTS
  Forty-one publications including a total of 43 case-control studies were selected for analysis. The overall data under a homozygote comparison model indicated a significant association of CYP2E1 RsaI/PstI polymorphisms with HNC risk (c2c2 vs c1c1: odds ratio [OR] = 1.97; 95% confidence interval [CI] = 1.53-2.53). Similar results were observed in the Asian subgroup (c2c2 vs c1c1: OR = 1.98; 95%CI = 1.51-2.60; c2 vs c1: OR = 1.20; 95%CI = 1.03-1.39) and mixed population (c2 vs c1: OR = 1.41; 95%CI = 1.06-1.86) when the data were stratified by ethnicities. Interestingly, increased cancer risk only was shown among never-smokers (c2c2+c1c2 vs c1c1: OR = 1.44; 95%CI = 1.05-1.98) but not ever-smokers.
  
  
  CONCLUSIONS
  CYP2E1 RsaI/PstI polymorphisms may modify the susceptibility to HNC, particularly among Asians, mixed population, and never-smokers. Future large and well-designed studies are needed to verify this conclusion.
authors: Department of Otolaryngology, Southwest Hospital, Third Military Medical University, Chongqing Affiliated Hospital of Guiyang Medical University, Guiyang Post-doctoral Scientific Research Station, Chongqing Cancer Institute, Chongqing, China.
authors: Xianlu
authors: X
authors: Zhuo
authors: Jue
authors: J
authors: Song
authors: Jian
authors: J
authors: Liao
authors: Wei
authors: W
authors: Zhou
authors: Huiping
authors: H
authors: Ye
authors: Qi
authors: Q
authors: Li
authors: Zhaolan
authors: Z
authors: Xiang
authors: Xueyuan
authors: X
authors: Zhang
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics* / Q000378:metabolism; D004273:DNA, Neoplasm / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D011110:Polymorphism, Genetic; D000077195:Squamous Cell Carcinoma of Head and Neck
chemical_list: D004273:DNA, Neoplasm; D019392:Cytochrome P-450 CYP2E1