Meta-analysis of the association between VEGF-634 G>C and risk of malignancy based on 23 case-control studies

The association between polymorphism of vascular endothelial growth factor (VEGF)-634 G > C and malignancy risk has been widely studied, and no conclusive result was available up to now. Twenty-three case-control studies with 21,917 individuals were included in this meta-analysis through searching the databases of Medline, Embase, and CNKI (up to October 1st, 2010). The odds ratio (OR) and 95% confidence interval (95%CI) were used to investigate the strength of the association. Overall, the pooled analysis showed that there was no association between VEGF-634 G > C and risk of malignancy, and the ORs (95%CIs) were 0.98 (0.85-1.12) for GG versus CC, 1.03 (0.90-1.17) for GC versus CC, 1.00 (0.89-1.13) for G carrier versus CC, and 1.08 (0.94-1.23) for C carrier versus GG. Subgroup analyses according to ethnicity, source of control, type of cancer, and sample size were also performed, and results indicated that VEGF-634 G > C was not associated with risk of malignancy for neither Asians [1.06 (0.81-1.38) for GG vs. CC and 1.08 (0.84-1.39) for GC vs. CC] nor Caucasians [0.93 (0.83-1.05) for GG vs. CC and 0.98 (0.87-1.10) for GC vs. CC]. It was also not associated with risk of breast cancer [0.95 (0.81-1.12) for GG vs. CC], gastric cancer [0.93 (0.47-1.84) for GG vs. CC], and colorectal cancer [1.17 (0.93-1.47) for GG vs. CC]. This meta-analysis suggests that VEGF-634 G > C may be not associated with risk of malignancy. More studies with larger sample size were needed to provide more precise evidence.