Interaction between IGF-1 polymorphisms and overweight for the risk of pancreatic cancer in Japanese
Nakao, M., Hosono, S., Ito, H., et al.
Although several reports have described a possible association between insulin-like growth factors-1 (IGF-1) and pancreatic cancer (PC) risk, this association has not been evaluated in the non-Caucasian population. To assess the impact of IGF-1 polymorphisms on PC risk in Japanese, we conducted a case-control study which compared the frequency of ten single nucleotide polymorphisms (SNPs) and haplotypes of IGF-1. SNPs were investigated using the TaqMan method in 176 patients with PC and 1402 control subjects. Exposure to risk factors was assessed from the results of a self-administered questionnaire. Associations and gene-environment interactions were examined using an unconditional logistic regression model. We did not observe any significant main effect of IGF-1 loci, but did find interactions between rs5742714 and past and/or current body-mass index (BMI) status. Among patients with BMI > 25 at age 20, an increased PC risk was observed with the addition of the minor allele for rs5742714 (trend P = 0.048) and rs6214 (P = 0.043). Among patients with current BMI > 25, an increased or decreased PC risk was observed with the addition of the minor allele for rs5742714 (trend P = 0.046), rs4764887 (P = 0.031) and rs5742612 (P = 0.038). Haplotype analysis of IGF-1 showed a significant association among patients who were either or both previously or currently overweight. These findings suggest that IGF-1 polymorphisms may affect the development of PC in the Japanese population in combination with obesity. Further studies to confirm these findings are warranted.
Nakao, M., Hosono, S., Ito, H., et al. "Interaction between IGF-1 polymorphisms and overweight for the risk of pancreatic cancer in Japanese" International Journal of Molecular Epidemiology and Genetics (2011): 354–66