title: Plasma insulin-like growth factor 1, insulin-like growth factor binding protein 3, and risk of colorectal cancer: a prospective study in northern Sweden.
abstract: BACKGROUND
  Insulin-like growth factor 1 (IGF-1) has antiapoptotic and mitogenic effects on various cell types, and raised IGF-1 levels are increasingly being implicated as potential risk factors for cancer.
  
  
  OBJECTIVE
  To examine the relationship between IGF-1 and its major plasma binding protein, IGF binding protein 3 (IGFBP-3), and the risk of colorectal cancer.
  
  
  METHODS
  We conducted a case-control study nested within the Northern Sweden Health and Disease Cohort. IGF-1 and IGFBP-3 were measured in prediagnostic plasma samples from 168 men and women who developed cancers of the colon (n=110) or rectum (n=58), and from 336 matched controls.
  
  
  RESULTS
  Conditional logistic regression analyses showed an increase in colon cancer risk with increasing levels of IGF-1 (odds ratios (ORs) 1.00, 1.89, 2.30, 2.66; p(trend)=0.03) and IGFBP-3 (ORs 1.00, 0.91, 1.80, 1.93; p(trend)=0.02). Rectal cancer risk was inversely related to levels of IGF-1 (ORs 1.00, 0.45, 0.33, 0.33; p(trend)=0.09) and IGFBP-3 (ORs 1.00, 0.75, 0.66, 0.49; p(trend)=0.21). Mutual adjustments between IGF-1 and IGFBP-3 did not materially alter these relationships.
  
  
  CONCLUSIONS
  These results support earlier findings of increased risk of colon cancer in subjects with elevated plasma IGF-1. Our results however do not support the hypothesis that the risk of rectal cancer could also be directly related to IGF-1 levels.
authors.affiliation: Department of Medical Biosciences, Pathology, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Palmqvist
authors.forename: G
authors.initials: G
authors.lastname: Hallmans
authors.forename: S
authors.initials: S
authors.lastname: Rinaldi
authors.forename: C
authors.initials: C
authors.lastname: Biessy
authors.forename: R
authors.initials: R
authors.lastname: Stenling
authors.forename: E
authors.initials: E
authors.lastname: Riboli
authors.forename: R
authors.initials: R
authors.lastname: Kaaks
mesh_terms: D000328:Adult; D000886:Anthropometry; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000097:blood*; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000097:blood*; D016017:Odds Ratio; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000097:blood*; D012307:Risk Factors
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D009363:Neoplasm Proteins; D007334:Insulin-Like Growth Factor I