Vascular endothelial growth factor +936C/T and +405G/C polymorphisms and cancer risk: a meta-analysis.

BACKGROUND AND AIMS: A number of investigators have studied the possible association between vascular endothelial growth factor (VEGF) polymorphisms and cancer risk, but the results have been conflicting. To examine the risk of cancer associated with the +936C/T and +405G/C polymorphisms of VEGF, all available studies were considered in the present meta-analysis. METHODS: We performed a computerized search of PubMed and Embase database for relevant studies. Articles meeting the inclusion criteria were reviewed systematically, and the reported data were aggregated using the statistical techniques of meta-analysis. RESULTS: Overall, the 936C allele showed no significant effect on cancer risk compared with the 936T allele in all subjects (OR = 0.77, 95% CI = 0.53-1.14; random model). Similarly, no significant effect of 405G allele compared with 405C on cancer risk was found (OR = 1.08, 95% CI = 0.94-1.24; random model). It indicated that the VEGF +936C/T and +405G/C polymorphisms might not be risk factors for cancer, but the 936C allele was associated with a decreased risk of oral cancer (OR = 0.72, 95% CI = 0.53-0.97; fixed model). CONCLUSIONS: The evidence from our meta-analysis supports that there was an association between 936C allele and decreased oral cancer risk, although no evidence of association between VEGF +936C/T or +405G/C polymorphism and cancer was observed in all examined patients. Further studies based on larger, stratified population are required to explore the role of VEGF polymorphisms on cancer risk.