Association between HLA-G 14-bp insertion/deletion polymorphism and cancer risk: a meta-analysis.

PURPOSE A number of studies have investigated the association between human leukocyte antigen-G (HLA-G) 14-bp insertion/deletion polymorphism and cancer risk, but the results remain controversial. In this study we aimed to clarify whether this association really exists. METHODS We carried out a meta-analysis of 8 studies including 1179 cases and 2795 controls from PubMed and Chinese language (CNKI and WanFang) databases to assess the association between the HLA-G 14-bp insertion/deletion polymorphism and cancer risk by pooled odds ratio (OR) and 95% confidence interval (CI). RESULTS The results showed that the HLA-G 14-bp insertion/ deletion polymorphism was not associated with total cancer risk in all genetic models (dominant model: OR=0.90, 95% CI-0.70-1.17; recessive model: OR=0.97, 95% CI=0.67-1.42; insertion/deletion (ID) vs deletion/deletion (DD):OR=0.88, 95% CI=0.66-1.18; insertion/insertion (II) vs DD: OR=0.94, 95% CI=0.62-1.41; insertion (I) vs deletion (D): OR=0.95, 95% CI=0.78-1.16). In the subgroup analysis by ethnicity, no significant association was found between Asians and Caucasians. However, subgroup analysis by cancer type showed that the polymorphism was associated with risk of hepatocellular carcinoma. CONCLUSIONS This meta-analysis suggests that HLA-G 14-bp insertion/deletion polymorphism may not influence the susceptibility of total cancer, but it is related to risk of hepatocellular carcinoma.