vascular endothelial growth factor -2578c/a polymorphism and colorectal cancer risk: a meta-analysis

background: the effects of the vascular endothelial growth factor (vegf) gene ?2578c/a polymorphism on colorectal cancer (crc) risk have been investigated in some studies; however, the results of these studies were conflicting and ambiguous. therefore, we aimed to do a meta-analysis to investigate the association of vegf ?2578c/a polymorphisms with crc risk from all eligible case-control studies published to date. materials and methods: an electronic search of the pubmed, embase and medline was performed. retrieve terms were utilized as following: (“vegf a” [mesh terms]) and (“polymorphism, genetic” [mesh terms]) and (“colorectal neoplasms” [mesh terms]). the association between vegf ?2578c/a polymorphisms with crc risk was calculated with odds ratios (ors) and their corresponding 95% of confidence intervals (cis), and stratified analysis was also conducted with respect to ethnicity. results: a comprehensive meta-analysis of eight studies, including 2312 cases and 2308 controls was performed in this work. combined analysis revealed that a significant association between the vegf ?2578c/a polymorphism with crc risk was identified in three comparison models including c allele versus a allele (or = 0.85, 95% ci 0.75-0.97, p = 0.02), aa versus ca + cc (or = 1.28, 95% ci 1.09-1.51, p = 0.003), and aa versus cc (or = 0.77, 95% ci 0.64-0.93, p = 0.006). moreover, a similar result was obtained in the subgroup analysis that comparison models of c allele versus. a allele (or = 0.85, 95% ci 0.76-0.95, p = 0.004), aa versus ca + cc (or = 1.31, 95% ci 1.09-1.57, p = 0.004), and aa versus cc (or = 0.73, 95% ci 0.59-0.90, p = 0.004) was confirmed to be associated with crc risk in caucasian. conclusion: it has been proved that the c allele versus a allele, aa versus ca + cc, and aa versus cc comparison models of vegf ?2578c/a polymorphism might be risk factors for crc, but further studies with larger sample sizes are required to make a better assessment of above association.