Association of glutathione S-transferase T1, M1 and P1 polymorphisms in the breast cancer risk: a meta-analysis in Asian population

Background: Published data regarding the associations between glutathione S-transferase (GST) T1, M1 and P1 polymorphisms and breast cancer risk are inconclusive. The aim of this study is to comprehensively evaluate the genetic risk of GST genes for breast cancer. Materials and Methods: A systematic literature search was carried out in Pubmed, Medline (Ovid), Embase, CBM, CNKI, Weipu, and Wanfang database, covering all publications (last search was performed on May 20, 2015). Statistical analysis was performed using Revman 5.2 and STATA 12.0 softwares. Results: A total of 12,035 cases and 13,911 controls in 34 case-control studies were included in this meta-analysis. The results suggested that the GSTM1 and GSTP1 polymorphisms can obviously increase the risk of breast cancer in Asian population (odds ratio (OR) = 1.18, 95% confidence interval (CI) = 1.04-1.33, P = 0.008 and OR = 1.23, 95% CI = 1.07-1.41, P = 0.003, respectively), especially in East Asian (OR = 1.14, 95% CI = 1.01-1.27, P = 0.03 and OR = 1.15, 95% CI = 1.03-1.28, P = 0.01, respectively) and hospital-based case-control study (HCC) group (OR = 1.32, 95% CI = 1.11-1.56, P = 0.001 and OR = 1.38, 95% CI = 1.03-1.84, P = 0.03, respectively), while the association between GSTT1 null genotype and breast cancer risk is not significant (OR = 1.08, 95% CI = 0.93-1.25, P = 0.3). Conclusions: This meta-analysis indicated that the GSTM1 and GSTP1 polymorphisms might significantly contribute to breast cancer susceptibility in Asian population, especially in East Asian, while the GSTT1 polymorphism might not be associated with breast cancer.