OBJECTIVE: Recent evidence suggests that genetic variations in the hypoxia inducible factor-1α (HIF-1α) gene may have an impact on an individual's susceptibility to gastrointestinal tract (GIT) cancer; but individually published results are inconclusive. This meta-analysis aims to derive a precise estimation of the association between a common polymorphism (C1772T; rs11549465 C>T) in the HIF-1α gene and susceptibility to GIT cancer. METHODS: An extensive literature search was conducted for appropriate articles published before May 1st, 2013. This meta-analysis was performed using the STATA 12.0 software. The crude odds ratio with 95% confidence interval was calculated. RESULTS: Six case-control studies were assessed with a total of 911 GIT cancer patients and 2774 healthy controls. Our meta-analysis indicated that the C variant of HIF-1α C1772T polymorphism appeared to confer an increased risk for GIT cancer. Further subgroup analyses indicated that the C variant of HIF-1α C1772T polymorphism may increase the risk of GIT cancer among Asian populations, but not among Caucasian populations. Univariate and multivariate meta-regression analyses confirmed that differences in ethnicity and cancer type are the major sources of heterogeneity. No publication bias was detected in this meta-analysis. CONCLUSION: The current meta-analysis suggests that the C variant of HIF-1α C1772T polymorphism may increase the risk of GIT cancer, especially among Asian populations.
OBJECTIVE: Recent evidence suggests that genetic variations in the hypoxia inducible factor-1α (HIF-1α) gene may have an impact on an individual's susceptibility to gastrointestinal tract (GIT) cancer; but individually published results are inconclusive. This meta-analysis aims to derive a precise estimation of the association between a common polymorphism (C1772T; rs11549465 C>T) in the HIF-1α gene and susceptibility to GIT cancer. METHODS: An extensive literature search was conducted for appropriate articles published before May 1st, 2013. This meta-analysis was performed using the STATA 12.0 software. The crude odds ratio with 95% confidence interval was calculated. RESULTS: Six case-control studies were assessed with a total of 911 GIT cancerpatients and 2774 healthy controls. Our meta-analysis indicated that the C variant of HIF-1α C1772T polymorphism appeared to confer an increased risk for GIT cancer. Further subgroup analyses indicated that the C variant of HIF-1α C1772T polymorphism may increase the risk of GIT cancer among Asian populations, but not among Caucasian populations. Univariate and multivariate meta-regression analyses confirmed that differences in ethnicity and cancer type are the major sources of heterogeneity. No publication bias was detected in this meta-analysis. CONCLUSION: The current meta-analysis suggests that the C variant of HIF-1α C1772T polymorphism may increase the risk of GIT cancer, especially among Asian populations.