Prostate carcinoma incidence in relation to prediagnostic circulating levels of insulin-like growth factor I, insulin-like growth factor binding protein 3, and insulin

Authors

  • Chu Chen Ph.D.,

    Corresponding author
    1. Program in Epidemiology, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
    2. Department of Otolaryngology: Head and Neck Surgery, University of Washington, Seattle, Washington
    3. Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, Washington
    • Program in Epidemiology, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Mailstop M5-C800, 1100 Fairview Avenue North, P.O. Box 19024, Seattle, WA 98109
    Search for more papers by this author
    • Fax: (206) 667-2537

  • S. Kay Lewis,

    1. Program in Epidemiology, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
    Search for more papers by this author
  • Lynda Voigt Ph.D.,

    1. Program in Epidemiology, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
    Search for more papers by this author
  • Annette Fitzpatrick Ph.D.,

    1. Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, Washington
    Search for more papers by this author
  • Stephen R. Plymate M.D.,

    1. Division of Gerontology and Geriatric Medicine, Department of Medicine, Harborview Medical Center, University of Washington, Seattle, Washington
    Search for more papers by this author
  • Noel S. Weiss M.D., Dr.P.H.

    1. Program in Epidemiology, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
    2. Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, Washington
    Search for more papers by this author

Abstract

BACKGROUND

There have been several epidemiologic studies investigating the association between circulating levels of insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 3 (IGFBP-3), and insulin in relation to the risk of prostate carcinoma, with conflicting results. To examine this issue further, the authors conducted a nested case–control study within the Cardiovascular Health Study cohort.

METHODS

In men who were diagnosed with prostate carcinoma (cases) between 1990 and 1999 (n = 174), the levels of IGF-I, IGFBP-3, and insulin were measured on blood samples that were obtained 1–9 years prior to diagnosis (mean, 3.4 years). Similar measurements were made on 174 male participants without prostate carcinoma (controls) who were matched to cases based on the year blood was drawn, survival until the date of diagnosis, race, and age.

RESULTS

Relative to the men with IGF-I levels in the first (lowest) quartile of the distribution, the risk of prostate carcinoma for men in the second, third, and fourth (upper) quartiles were 0.77 (95% confidence interval [95% CI], 0.43–1.38), 0.73 (95% CI, 0.41–1.30), and 0.67 (95% CI, 0.37–1.25), respectively. The results were influenced little by adjustment for levels of IGFBP-3 or, instead, by evaluating the molar IGF-I/IGFBP-3 ratio. An analysis that was restricted to men who had plasma prostate-specific antigen levels < 4 ng/mL at the time of the blood draw yielded similar results. The corresponding relative risks for IGFBP-3 were 0.91 (95% CI, 0.49–1.68), 0.47 (95% CI, 0.25–0.94), and 0.65 (95% CI, 0.35–1.20), respectively. The distribution of serum insulin levels in cases and controls were nearly identical.

CONCLUSIONS

The IGF-I level was not associated positively with the risk of prostate carcinoma; however, an increase in the IGFBP-3 level was associated with a modest decrease in risk. Cancer 2005. © 2004 American Cancer Society.

Ancillary