@article {810, title = {Prostate carcinoma incidence in relation to prediagnostic circulating levels of insulin-like growth factor I, insulin-like growth factor binding protein 3, and insulin.}, journal = {Cancer}, volume = {103}, year = {2005}, month = {2005 Jan 01}, pages = {76-84}, 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.

}, keywords = {Aged, Aged, 80 and over, Carcinoma, Case-Control Studies, Humans, Hypoglycemic Agents, Incidence, Insulin, Insulin-Like Growth Factor Binding Protein 3, Insulin-Like Growth Factor I, Male, Prostatic Neoplasms, Risk Factors}, issn = {0008-543X}, doi = {10.1002/cncr.20727}, author = {Chen, Chu and Lewis, S Kay and Voigt, Lynda and Fitzpatrick, Annette and Plymate, Stephen R and Weiss, Noel S} } @article {1055, title = {Insulin-like growth factors, their binding proteins, and prostate cancer risk: analysis of individual patient data from 12 prospective studies.}, journal = {Ann Intern Med}, volume = {149}, year = {2008}, month = {2008 Oct 07}, pages = {461-71, W83-8}, abstract = {

BACKGROUND: Some, but not all, published results have shown an association between circulating blood levels of some insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) and the subsequent risk for prostate cancer.

PURPOSE: To assess the association between levels of IGFs and IGFBPs and the subsequent risk for prostate cancer.

DATA SOURCES: Studies identified in PubMed, Web of Science, and CancerLit.

STUDY SELECTION: The principal investigators of all studies that published data on circulating concentrations of sex steroids, IGFs, or IGFBPs and prostate cancer risk using prospectively collected blood samples were invited to collaborate.

DATA EXTRACTION: Investigators provided individual participant data on circulating concentrations of IGF-I, IGF-II, IGFBP-II, and IGFBP-III and participant characteristics to a central data set in Oxford, United Kingdom.

DATA SYNTHESIS: The study included data on 3700 men with prostate cancer and 5200 control participants. On average, case patients were 61.5 years of age at blood collection and received a diagnosis of prostate cancer 5 years after blood collection. The greater the serum IGF-I concentration, the greater the subsequent risk for prostate cancer (odds ratio [OR] in the highest vs. lowest quintile, 1.38 [95\% CI, 1.19 to 1.60]; P < 0.001 for trend). Neither IGF-II nor IGFBP-II concentrations were associated with prostate cancer risk, but statistical power was limited. Insulin-like growth factor I and IGFBP-III were correlated (r = 0.58), and although IGFBP-III concentration seemed to be associated with prostate cancer risk, this was secondary to its association with IGF-I levels. Insulin-like growth factor I concentrations seemed to be more positively associated with low-grade than high-grade disease; otherwise, the association between IGFs and IGFBPs and prostate cancer risk had no statistically significant heterogeneity related to stage or grade of disease, time between blood collection and diagnosis, age and year of diagnosis, prostate-specific antigen level at recruitment, body mass index, smoking, or alcohol intake.

LIMITATIONS: Insulin-like growth factor concentrations were measured in only 1 sample for each participant, and the laboratory methods to measure IGFs differed in each study. Not all patients had disease stage or grade information, and the diagnosis of prostate cancer may differ among the studies.

CONCLUSION: High circulating IGF-I concentrations are associated with a moderately increased risk for prostate cancer.

}, keywords = {Aged, Humans, Insulin-Like Growth Factor Binding Protein 2, Insulin-Like Growth Factor Binding Protein 3, Insulin-Like Growth Factor Binding Proteins, Insulin-Like Growth Factor I, Insulin-Like Growth Factor II, Male, Middle Aged, Prospective Studies, Prostatic Neoplasms, Risk Factors, Somatomedins}, issn = {1539-3704}, doi = {10.7326/0003-4819-149-7-200810070-00006}, author = {Roddam, Andrew W and Allen, Naomi E and Appleby, Paul and Key, Timothy J and Ferrucci, Luigi and Carter, H Ballentine and Metter, E Jeffrey and Chen, Chu and Weiss, Noel S and Fitzpatrick, Annette and Hsing, Ann W and Lacey, James V and Helzlsouer, Kathy and Rinaldi, Sabina and Riboli, Elio and Kaaks, Rudolf and Janssen, Joop A M J L and Wildhagen, Mark F and Schr{\"o}der, Fritz H and Platz, Elizabeth A and Pollak, Michael and Giovannucci, Edward and Schaefer, Catherine and Quesenberry, Charles P and Vogelman, Joseph H and Severi, Gianluca and English, Dallas R and Giles, Graham G and Stattin, P{\"a}r and Hallmans, G{\"o}ran and Johansson, Mattias and Chan, June M and Gann, Peter and Oliver, Steven E and Holly, Jeff M and Donovan, Jenny and Meyer, Fran{\c c}ois and Bairati, Isabelle and Galan, Pilar} }