Serum insulin-like growth factor (IGF)-I and IGF-binding protein-3 concentrations and prostate cancer risk: results from the European Prospective Investigation into Cancer and Nutrition.
BACKGROUND
Some studies suggest that elevated serum insulin-like growth factor (IGF)-I concentrations are associated with an increased risk of prostate cancer and, in particular, with an increased risk of advanced-stage prostate cancer.


METHODS
We analyzed the association between prediagnostic serum concentrations of IGF-I and IGF-binding protein-3 (IGFBP-3) and prostate cancer risk in a case-control study nested in the European Prospective Investigation into Cancer and Nutrition. This study includes 630 incident prostate cancer cases and 630 matched control subjects. Odds ratios and their 95% confidence intervals (95% CI) were calculated for prostate cancer risk associated with increasing IGF-I and IGFBP-3 concentrations using conditional logistic regression.


RESULTS
The risk of total prostate cancer in the highest versus the lowest third of serum peptide concentration was 1.35 (95% CI, 0.99-1.82; Ptrend = 0.08) for IGF-I, 1.39 (95% CI, 1.02-1.89; Ptrend = 0.12) for the IGF-I residuals after adjusting for IGFBP-3, 1.22 (95% CI, 0.92-1.64; Ptrend = 0.38) for IGFBP-3, and 1.01 (95% CI, 0.74-1.37; Ptrend = 0.75) for the IGFBP-3 residuals after adjusting for IGF-I. There was no significant difference in the association of peptide hormones and prostate cancer by stage of disease, although the association of serum IGF-I concentration with risk was slightly stronger for advanced-stage disease; the odds ratio for the highest versus the lowest third was 1.65 (95% CI, 0.88-3.08; Ptrend = 0.21) for IGF-I and 1.76 (95% CI, 0.92-3.40; Ptrend = 0.11) for IGF-I adjusted for IGFBP-3.


CONCLUSIONS
In this large nested case-control study, serum IGF-I concentration is not strongly associated with prostate cancer risk, although the results are compatible with a small increase in risk, particularly for advanced-stage disease; no association for IGFBP-3 was observed.
Allen
Naomi E
NE
Cancer Research UK Epidemiology Unit, University of Oxford, Oxford OX3 7LF, United Kingdom. naomi.allen@ceu.ox.ac.uk
Key
Timothy J
TJ
Appleby
Paul N
PN
Travis
Ruth C
RC
Roddam
Andrew W
AW
Rinaldi
Sabina
S
Egevad
Lars
L
Rohrmann
Sabine
S
Linseisen
Jakob
J
Pischon
Tobias
T
Boeing
Heiner
H
Johnsen
Nina Føns
NF
Tjønneland
Anne
A
Grønbaek
Henning
H
Overvad
Kim
K
Kiemeney
Lambartus
L
Bueno-de-Mesquita
H Bas
HB
Bingham
Sheila
S
Khaw
Kay Tee
KT
Tumino
Rosario
R
Berrino
Franco
F
Mattiello
Amalia
A
Sacerdote
Carlotta
C
Palli
Domenico
D
Quirós
José Ramón
JR
Ardanaz
Eva
E
Navarro
Carmen
C
Larrañaga
Nerea
N
Gonzalez
Carlos
C
Sanchez
Maria-José
MJ
Trichopoulou
Antonia
A
Travezea
Cryssoula
C
Trichopoulos
Dimitrios
D
Jenab
Mazda
M
Ferrari
Pietro
P
Riboli
Elio
E
Kaaks
Rudolf
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology*; D012307:Risk Factors
D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I