title: GSTM1 null genotype is associated with increased risk of gastric cancer in both ever-smokers and non-smokers: a meta-analysis of case-control studies.
abstract: Previous studies have suggested that the glutathione S-transferases M1 (GSTM1) null genotype is associated with the risk of gastric cancer. However, the interaction between GSTM1 null genotype and smoking for the risk of gastric cancer is still elusive. Therefore, we performed a meta-analysis to ascertain this issue. Databases of PubMed, EMBASE, and China National Knowledge Infrastructure were searched to retrieve relevant studies. Smokers were categorized as "ever-smokers" and "non-smokers." Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to estimate the association strength. Subgroup analyses according to ethnicity, source of control, and sample size were also conducted. A total of 15 eligible studies, including 4,687 gastric cancer cases and 7,002 controls, were identified. We found that the GSTM1 null genotype was associated with increased risk of gastric cancer among ever-smokers (OR = 1.460, 95% CI 1.064-2.003, heterogeneity: P = 0.019). The null genotype also significantly increased the risk of gastric cancer among non-smokers (OR = 1.777, 95% CI 1.301-2.426, heterogeneity: P < 0.01). Stratified analysis according to ethnicity showed that the GSTM1 null genotype was associated with increased risk of gastric cancer among Asians both in ever-smokers (OR = 1.841, 95% CI 1.184-2.861) and non-smokers (OR = 1.773, 95% CI 1.382-2.275). In conclusion, the GSMT1 null genotype significantly increased the risk of gastric cancer both in ever-smokers and non-smokers.
authors: Department of Oncology, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.
authors: Jianchun
authors: J
authors: Gu
authors: Hanqing
authors: H
authors: Zou
authors: Leizhen
authors: L
authors: Zheng
authors: Xiaoping
authors: X
authors: Li
authors: Siyu
authors: S
authors: Chen
authors: Li
authors: L
authors: Zhang
mesh_terms: D016022:Case-Control Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D012306:Risk; D012907:Smoking / Q000009:adverse effects*; D013274:Stomach Neoplasms / Q000209:etiology / Q000235:genetics*
chemical_list: D005982:Glutathione Transferase