Serum insulin-like growth factor-I levels and prostatic intraepithelial neoplasia: a clue to the relationship between IGF-I physiology and prostate cancer risk.
Serum insulin-like growth factor-I (IGF-I) levels at the higher end of the reference range have been associated with increased risk for the future development of prostate cancer. We determined whether high serum IGF-I levels are associated with precancerous lesions of the prostate. We conducted a case-control study to determine whether high serum IGF-I levels were associated with the presence of high-grade prostatic intraepithelial neoplasia (HGPIN) among patients who presented for prostate biopsy because of an abnormal serum prostate-specific antigen level or digital rectal exam. We measured serum IGF-I and insulin-like growth factor binding protein-3 (IGFBP-3) prior to prostate biopsy and compared them between 103 men with HGPIN (cases) and 205 men with normal prostate histology (controls). The mean IGF-I level in patients with HGPIN (130.2 ng/mL) was significantly higher compared with controls (118.8 ng/mL, P = 0.01). The mean IGFBP-3 level in patients with HGPIN (2,393.9 ng/mL) was also higher compared with controls (2,276.0 ng/mL, P = 0.06). After adjusting for age, prostate-specific antigen, digital rectal examination, and ethnic background, the odds ratio for a HGPIN diagnosis among men in the highest relative to the lowest quartile of serum IGF-I level was 1.94 (95% confidence interval, 1.0-3.7; P = 0.04). The potential association between a high serum IGF-I level and the presence of HGPIN may represent an important clue to understanding the basis for the relationship between IGF-I physiology and prostate cancer risk. Larger studies will be required to confirm this relationship.
Nam
Robert K
RK
Sunnybrook and Women's College Health Sciences Centre, 2075 Bayview Avenue, MG-406 Toronto, Ontario, Canada, M4N 3M5. robert.nam@utoronto.ca
Trachtenberg
John
J
Jewett
Michael A S
MA
Toi
Ants
A
Evans
Andrew
A
Emami
Marjan
M
Narod
Steven A
SA
Pollak
Michael
M
D000368:Aged; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D017430:Prostate-Specific Antigen / Q000097:blood; D019048:Prostatic Intraepithelial Neoplasia / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D012307:Risk Factors
D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D017430:Prostate-Specific Antigen