Abstract
INTRODUCTION: The transforming growth factor β (TGF-β) signaling system plays an important role in carcinogenesis. Alteration of TGF-β receptors is a potential mechanism in the development and progression of human cancers. Several studies have investigated the association between TGFBR1 gene Int7G24A and cancer risk, but the results are still inconclusive, so a meta-analysis is needed to verify the association. MATERIAL AND METHODS: We carried out a literature search using the PubMed database (up to January 2012) to identify all papers that investigated the association between the Int7G24A polymorphism (rs334354) and cancer risk. The inclusion criteria were: (1) evaluation of the Int7G24A polymorphism and cancer risk, (2) case-control studies, (3) sufficient published data about genotype frequency. Also the strength of the association between Int7G24A polymorphism and cancer was measured by odds ratio (OR), which was calculated according to the method of Woolf. A χ(2)-based Q statistic test was performed to assess the between-study heterogeneity. RESULTS: There are 10 studies including 2398 cases and 3465 controls in the research. Our results indicate that the TGFBR1 gene Int7G24A polymorphism is associated with cancer risk (A vs. G: OR = 1.35, 95% CI = 1.10-1.66, A/A+G/A vs. G/G: OR = 1.34, 95% CI = 1.05-1.72). CONCLUSIONS: This meta-analysis suggests that the TGFBR1 gene Int7G24A polymorphism might be associated with an increased risk of cancer.