Association Between Two Functional Polymorphisms of Insulin-Like Growth Factor Binding Protein 3 and Colorectal Cancer Risk in a Chinese Population

Circulating levels of insulin-like growth factor binding protein 3 (IGFBP3) are modulated by functional variants of IGFBP3 and therefore may be associated with higher risk of colorectal cancer development. However, few studies have investigated the role of IGFBP3 polymorphisms in colorectal cancer in Chinese individuals. In this study, two common polymorphisms of IGFBP3 were determined by the Taqman genotyping platform in 202 Chinese colorectal cancer cases diagnosed between 2006 and 2008 and 212 cancer-free population controls. Data showed that the genotype distribution of G2133C (rs2864746), but not A-202C (rs2864744), was significantly different between cancer cases and controls. Unconditional logistic regression analyses revealed that participants carrying the G2133C GC heterozygote or CC homozygote had a significant 1.55-fold increased risk of colorectal cancer development in an allele dose-responsive manner. However, there was no evidence of a dose-effect relationship between number of variants and risk for CRC occurrence. Data suggest that the exon 1 G2133C missense variant of IGFBP3 may be a susceptibility factor for colorectal cancer in Chinese subjects. Larger studies are warranted to validate our findings in a Chinese population.