Serum levels of insulin-like growth factor-1 and insulin-like growth factor-1 binding proteins after radical prostatectomy.
OBJECTIVE
Elevated serum levels of insulin-like growth factor-1 (IGF-1) have been consistently shown to be a risk factor for prostate cancer. Alterations in serum IGF-1 binding proteins 1 to 3 have also been associated with prostate cancer risk. A potentially important complication in these studies is that prostate tissue, perhaps especially malignant prostate tissue, may secrete IGF-1 and its binding proteins into serum. In fact, it is possible that altered levels of these proteins observed in subjects at risk for prostate cancer are the result of prostate cancer rather than related to its cause.


METHODS
The contribution of prostate cancer to serum levels of IGF-1 and IGF-1 binding proteins was determined by analyzing serum samples from 86 patients with prostate cancer 2 weeks before and 8 weeks after radical prostatectomy. Preoperative and postoperative values for IGF-1 and its 3 major binding proteins were analyzed using univariate and multivariate analysis models.


RESULTS
On univariate analysis significant increases and not decreases in IGF-1, IGF binding protein-1 and 3 were observed after prostatectomy. On multivariate analysis a significant post-prostatectomy increase was observed for IGF-1 binding proteins 1 and 3 but the increase in IGF-1 was not significant.


CONCLUSIONS
Increased levels of IGF-1 and IGF-1 binding proteins were unexpected after prostatectomy. This result makes it extremely unlikely that secretion from the prostate, even if it contains cancer, affects serum levels of these proteins. The implication of these findings is that endocrine production of IGF-1 is a factor in prostate cancer risk. Therefore, strategies to lower serum IGF-1 may be potentially useful.
Bubley
Glenn J
GJ
Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
Balk
Steve P
SP
Regan
Meredith M
MM
Duggan
Stephen
S
Morrissey
Mary Ellen
ME
Dewolf
William C
WC
Salgami
Ellena
E
Mantzoros
Christos
C
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000097:blood*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000601:surgery*; D012016:Reference Values; D012306:Risk
D014408:Biomarkers, Tumor; D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3