Genetic Association between the XPG Asp1104His Polymorphism and Head and Neck Cancer Susceptibility: Evidence Based on a Meta-Analysis

Background: Previous studies evaluating the association between the xeroderma pigmentosum group G(XPG) Asp1104His polymorphism and head and neck cancer susceptibility have proven controversial. Thismeta-analysis of the literature was performed to obtain a more precise estimation of the relationship. Materialsand
Methods: We systematically searched PubMed, Embase and Web of Science with a time limit of Dec 18,2014. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of any association.
Results: We performed a meta-analysis of eight published case-control studies, including 3,621 cases and 5,475controls. Overall, no significant association was found between the XPG Asp1104His polymorphism and head andneck cancer susceptibility under all genetic models. In the subgroup analysis by ethnicity, the XPG Asp1104Hispolymorphism had statistically significant association with elevated head and neck cancer risk under CC vs GG(OR=1.24, 95% CI=1.00~1.54) and the recessive model (OR=1.22, 95%CI=1.01~1.46) in Asian populations. Asimilar result was found under CC vs GG (OR =1.22, 95%CI =1.01~1.47) in the population based subgroup bysource of control. When performed by tumor site, the XPG Asp1104His polymorphism had statistically significantassociation with elevated laryngeal cancer under all genetic models (CC vs GG: OR=1.59, 95% CI=1.16~2.19; GCvs GG: OR=1.38, 95%CI=1.10~1.72; dominant model: OR=1.42, 95% CI=1.15~1.74; recessive model: OR=1.36,95% CI=1.02~1.81).
Conclusions: This meta-analysis suggested that the XPG Asp1104His polymorphism is arisk factor for head and neck cancer susceptibility, especially for laryngeal cancer and in Asian populations.