Genetic Variants in the Insulin-like Growth Factor Pathway and Colorectal Cancer Risk in the Netherlands Cohort Study

Sci Rep. 2015 Sep 18;5:14126. doi: 10.1038/srep14126.

Abstract

Interrelationships between insulin-like growth factors (IGFs), hyperinsulinaemia, diabetes, and colorectal cancer (CRC) indicate involvement of IGFs in colorectal tumorigenesis. We investigated the CRC risk associated with 24 single nucleotide polymorphisms (SNPs) in 9 genes related to the IGF pathway and an IGF1 19-CA repeat polymorphism. Variants were selected from literature and genotyped in toenail DNA from 3,768 subcohort members and 2,580 CRC cases from the Netherlands Cohort Study, which has a case-cohort design (n = 120,852). We used the follow-up period 1986-2002. Eighteen SNPs were unequivocally associated with selected endpoints in the literature and unfavorable alleles were aggregated into a genetic sum score. Cox regression showed that a higher genetic sum score significantly increased CRC risk at all subsites, except the rectum, in men (highest vs. lowest tertile: HR for CRC = 1.36, 95% CI: 1.11, 1.65; P-trend = 0.002). Single SNPs (except the IGF1 SNP rs5742694) were not associated with risk. Models including the total number of IGF1 19-CA repeats showed CRC risk was halved at all subsites in women carrying < 38 repeats but not > 38 repeats (≤ 36 versus 38 repeats: HR for CRC = 0.44; 95% CI: 0.33, 0.58; P-trend < 0.001). These findings support a role for variants in IGF-related genes in colorectal tumorigenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alleles
  • Colorectal Neoplasms / epidemiology*
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / metabolism
  • Female
  • Gene Frequency
  • Genetic Association Studies
  • Genetic Predisposition to Disease*
  • Genetic Variation*
  • Genotype
  • Humans
  • Male
  • Middle Aged
  • Netherlands / epidemiology
  • Polymorphism, Single Nucleotide
  • Proportional Hazards Models
  • Risk
  • Signal Transduction
  • Somatomedins / genetics*
  • Somatomedins / metabolism

Substances

  • Somatomedins