High levels of circulating insulin-like growth factor-I increase prostate cancer risk: a prospective study in a population-based nonscreened cohort

J Clin Oncol. 2004 Aug 1;22(15):3104-12. doi: 10.1200/JCO.2004.10.105.


Purpose: Insulin-like growth factor-I (IGF-I) stimulates proliferation and inhibits apoptosis in prostate cancer cells, and IGF-I has been associated with increased prostate cancer risk in some, but not all, epidemiologic studies.

Subjects and methods: We extended our previous case-control study nested in the Northern Sweden Health and Disease Cohort, a population-based cohort from a region where little prostate specific antigen (PSA) screening is done. Levels of IGF-I and IGF binding protein-3 (IGFBP-3) were measured in prediagnostic blood samples from a total of 281 men who were subsequently diagnosed with prostate cancer after recruitment (median, 5 years after blood collection) and from 560 matched controls.

Results: Logistic regression analyses showed increases in prostate cancer risk with increasing plasma peptide levels, up to an odds ratio (OR) for top versus bottom quartile of IGF-I of 1.67 (95% CI, 1.02 to 2.71; Ptrend = .05), which was attenuated after adjustment for IGFBP-3 to an OR of 1.47 (95% CI, 0.81 to 2.64; P (trend) =.32). For men younger than 59 years at recruitment, OR for top versus bottom quartile of IGF-I was 4.12 (95% CI, 1.01 to 16.70; Ptrend = .002), which was significantly stronger than for men older than 59 years (P (interaction) = .006). For men with advanced cancer, OR for top versus bottom quartile of IGF-I was 2.87 (95% CI, 1.01 to 8.12; Ptrend = .10).

Conclusion: Our data add further support for IGF-I as an etiologic factor in prostate cancer and indicate that circulating IGF-I levels measured at a comparatively young age may be most strongly associated with prostate cancer risk.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cohort Studies
  • Humans
  • Insulin-Like Growth Factor Binding Protein 3 / blood
  • Insulin-Like Growth Factor I / analysis*
  • Logistic Models
  • Male
  • Middle Aged
  • Prospective Studies
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / etiology*
  • Risk Factors


  • Insulin-Like Growth Factor Binding Protein 3
  • Insulin-Like Growth Factor I