Glutathione S-transferase M1 gene polymorphism and laryngeal cancer risk: a meta-analysis.
OBJECTIVE
Studies investigating the association between glutathione S-transferase M1 (GSTM1) gene polymorphism and laryngeal cancer risk have reported conflicting results. The aim of the present study was to conduct a meta-analysis assessing the possible associations of GSTM1 gene polymorphism with laryngeal cancer risk.


METHODS
The relevant studies were identified through a search of PubMed, Embase, ISI Web of Knowledge and Chinese National Knowledge Infrastructure until May 2011 and selected on the basis of the established inclusion criteria for publications, then a meta-analysis was performed to quantitatively summarize association of GSTM1 polymorphism with laryngeal cancer susceptibility.


RESULTS
Seventeen studies were included in the present meta-analysis (2,180 cases and 2,868 controls). The combined results based on all studies showed that GSTM1 null genotype was associated with increased laryngeal cancer risk (OR = 1.17, 95% CI = 1.04∼1.31). When stratifying for race, GSTM1 null genotype exhibited increased laryngeal cancer risk in Caucasians (OR = 1.15, 95% CI = 1.01∼1.31), while no significant association was detected in Asians (OR = 1.25, 95% CI = 0.80∼1.96). In the subgroup analysis based on source of controls, significant associations were observed in the population-based studies (OR = 1.15, 95% CI = 1.01∼1.31) yet not in the hospital-based studies (OR = 1.25, 95% CI = 0.93∼1.67). Furthermore, in the subgroup analysis based on sample size, significant associations were also found in studies with at least 50 cases and 50 controls (OR = 1.15, 95% CI = 1.02∼1.30) but not in studies with fewer than 50 cases or 50 controls (OR = 1.46, 95% CI = 0.87∼2.46).


CONCLUSIONS
This meta-analysis supported that the GSTM1 gene polymorphism was associated with laryngeal cancer, particularly in Caucasians, and these associations varied in different subgroup, which indicated that population-based study with larger sample size was more appropriate in design of future study.
Department of Otolaryngology-Head and Neck Surgery, Shanghai First People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. yingxinjiang@126.com
Xin-Jiang
XJ
Ying
Pin
P
Dong
Bin
B
Shen
Cheng-Zhi
CZ
Xu
Hong-Ming
HM
Xu
Shu-Wei
SW
Zhao
D020022:Genetic Predisposition to Disease; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics*; D011110:Polymorphism, Genetic; D017594:Publication Bias; D012306:Risk
D005982:Glutathione Transferase