Association of VEGF-2549I/D promoter polymorphism with gastrointestinal tract cancer risk: a meta-analysis

Gastrointestinal tract (GIT) cancers are complex disorders affecting millions of people worldwide. The vascular endothelial growth factor (VEGF) helps in the development of different GIT cancers by promoting abnormal angiogenesis in cancer cells. The role of VEGF-2549I/D polymorphism in influencing GIT cancer susceptibility has been studied in different populations with inconclusive results. Therefore, the relationship between VEGF-2549I/D polymorphism with GIT susceptibility was studied by performing a meta-analysis study. Various online databases were used for identifying the articles. Based on study selection criteria, five studies on different GIT cancers including 1178 patients and 1520 controls were included in the meta-analysis. The accuracy of the study results was determined by performing a trial sequential analysis. In this study, the VEGF-2549I/D polymorphism did not influence the GIT cancer susceptibility in the overall analysis as well as when stratified according to ethnicity (p > 0.05). Stratification of all the studies based on the different GIT cancers reported an increased susceptibility to gastric cancer under different genetic models including allele contrast (OR = 1.67, CI = 1.294–2.157, p = 0.00008), recessive (OR = 1.68, CI = 1.056–2.660, p = 0.029), dominant (OR = 2.49, CI = 1.617–3.823, p = 0.00003), over-dominant (OR = 1.52, CI = 1.055–2.177, p = 0.025), II vs DD (OR = 2.97, CI = 1.692–5.208, p = 0.00015) and ID vs DD model (OR = 2.35, CI = 1.501–3.669, p = 0.00018). There was no relationship between VEGF-2549I/D promoter polymorphism and GIT cancer susceptibility in the overall population and also in different ethnic groups. Stratification analysis revealed higher susceptibility towards gastric cancer development with VEGF-2549I/D polymorphism.