Association of glutathione S-transferase T1, M1, and P1 polymorphisms in the breast cancer risk: a meta-analysis.
BACKGROUND
Several case-control studies investigating the relationship between genetic polymorphisms of glutathione S-transferase (GST) M1, GSTT1, and GSTP1 (rs1695) and the risk of breast cancer have reported contradictory results. We therefore performed a meta-analysis to clarify this issue.


METHODS
An updated meta-analysis using PubMed and Web of Knowledge databases for the eligible case-control studies was performed. Random- or fixed-effects model was used.


RESULTS
A total of 10,067 cancer cases and 12,276 controls in 41 independent case-control studies from 19 articles were included in this meta-analysis. Significant increase in risk of breast cancer for Asians was found in GSTM1-null genotype (P=0.012, odds ratio [OR] =1.17, 95% confidence interval [CI] =1.04-1.32) and GSTT1-null genotype (P=0.039, OR =1.19, 95% CI =1.01-1.41). In addition, our results showed that the GSTP1 (rs1695) polymorphisms can significantly increase the risk among Caucasians (P=0.042, OR =1.16, 95% CI =1.01-1.34). Sensitivity analysis and publication bias further confirmed the dependability of the results in this meta-analysis.


CONCLUSIONS
Our results demonstrate that both GSTM1- and GSTT1-null polymorphisms are associated with an increased risk of breast cancer in Asians and that GSTP1 Val105Ile (rs1695) polymorphism is associated with an increased breast cancer risk in Caucasians.
Department of Oncology, Shanghai East Hospital, Tongji University, Shanghai, People's Republic of China.
Zhiwang
Z
Song
Department of Neurosurgery, The Second Clinical Medical College of North Sichuan Medical College, Nanchong, Sichuan, People's Republic of China.
Chuan
C
Shao
Department of Oncology, Shanghai East Hospital, Tongji University, Shanghai, People's Republic of China.
Chan
C
Feng
Department of Oncology, Shanghai East Hospital, Tongji University, Shanghai, People's Republic of China.
Yonglin
Y
Lu
Department of Oncology, Shanghai East Hospital, Tongji University, Shanghai, People's Republic of China.
Yong
Y
Gao
Department of Oncology, Shanghai East Hospital, Tongji University, Shanghai, People's Republic of China.
Chunyan
C
Dong
GSTM1; GSTP1; GSTT1; breast cancer; meta-analysis; polymorphism