title: Glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) null polymorphisms, smoking, and their interaction in oral cancer: a HuGE review and meta-analysis.
abstract: The association between glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) null polymorphisms and oral cancer is not consistent across studies, and data on their interaction with smoking in oral cancer are lacking. The authors systematically searched PubMed and SciVerse Scopus for case-control studies examining the association between null genotypes of the GSTM1 and GSTT1 genes and oral cancer. Twenty-eight case-control studies published in English were identified. Summary odds ratios were derived via random-effects models. The summary odds ratio for the GSTM1 null genotype was 1.43 in Asians (95% confidence interval (CI): 1.14, 1.78; P < 0.01, I (2) = 73%) and 0.98 in Caucasians (95% CI: 0.76, 1.28; P = 0.91, I (2) = 0%). Case-only analysis of 6 studies (552 cases) showed an inverse multiplicative interaction between GSTM1 null polymorphisms and smoking (ever/high levels of smoking vs. never/low levels) (odds ratio (OR) = 0.51, 95% CI: 0.32, 0.82; P = 0.01, I (2) = 34%). The GSTT1 null genotype was not significantly associated with oral cancer in Asians (OR = 1.07, 95% CI: 0.82, 1.38; P = 0.63, I (2) = 65%) or Caucasians (OR = 1.04, 95% CI: 0.41, 2.65; P = 0.93, I (2) = 55%). In conclusion, the GSTM1 null genotype may be associated with a higher risk of oral cancer in Asians but not in Caucasians, and this effect may be modified by smoking status. The GSTT1 null genotype may not be associated with oral cancer.
authors: Department of Epidemiology, School of Public Health, Shanghai Jiao Tong University, 227 Chongqing South Road, Shanghai, China. zhang.zj@msn.com
authors: Zhi-Jiang
authors: ZJ
authors: Zhang
authors: Ke
authors: K
authors: Hao
authors: Rong
authors: R
authors: Shi
authors: Genming
authors: G
authors: Zhao
authors: Guo-Xin
authors: GX
authors: Jiang
authors: Yiqing
authors: Y
authors: Song
authors: Xiaohui
authors: X
authors: Xu
authors: Jin
authors: J
authors: Ma
mesh_terms: D044466:Asian People; D056726:Genetic Association Studies; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D009062:Mouth Neoplasms / Q000201:enzymology / Q000235:genetics*; D011110:Polymorphism, Genetic; D012907:Smoking / Q000235:genetics*; D044465:White People
chemical_list: D005982:Glutathione Transferase; C413545:glutathione S-transferase T1