Meta-Analysis of the Association between Insulin-Like Growth Factor Binding Protein 3 Genetic Polymorphisms and Colorectal Cancer Susceptibility

Insulin-like growth factor binding protein 3 (IGFBP-3) plays an important role in the development and progress of cancers. The association between IGFBP-3 polymorphisms and colorectal cancer remains controversial and ambiguous. The aim of this study is to explore the association between IGFBP3 A-202C and Gly32Ala polymorphisms and colorectal cancer susceptibility using meta-analysis. Case-control studies on the association between IGFBP3 A-202C and Gly32Ala polymorphisms and colorectal cancer, which had sufficient data for estimating an odds ratio (OR) with 95% confidence interval (CI), were included in the meta-analysis. Abstracts, case reports, editorials, and review articles were excluded. Heterozygous and homozygous mutants were compared with the wild types to estimate combined OR values and 95%CIs with Review Manager 5.0. Six eligible studies were included, with 3157 patients and 6027 controls for A-202C and 1711 patients and 2995 controls for Gly32Ala. No significant association was found in all genetic models (for A-202C, AC vs. AA, OR = 0.99(0.88-1.11), CC vs. AA, OR = 1.06(0.92-1.22), dominant model, OR = 0.98(0.88-1.09), recessive model, OR = 0.94(0.84-1.05); and for Gly32Ala polymorphism, GC vs. GG, OR = 1.10(0.92-1.31), CC vs. GG, OR = 0.93(0.76-1.14), dominant model, OR = 1.05(0.89-1.24), recessive model, OR = 0.90(0.77-1.05)). The results suggest that the IGFBP3 A-202C and Gly32Ala polymorphisms are not associated with colorectal cancer susceptibility.