title: Insulin-like growth factor-I concentration and risk of prostate cancer: results from the European Prospective Investigation into Cancer and Nutrition.
abstract: BACKGROUND
  High circulating insulin-like growth factor-I (IGF-I) concentrations have been associated with increased risk for prostate cancer in several prospective epidemiological studies. In this study, we investigate the association between circulating IGF-I concentration and risk of prostate cancer over the long term in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.
  
  
  METHODS
  In a nested case-control design, 1,542 incident prostate cancer cases from eight European countries were individually matched to 1,542 controls by study center, age at recruitment, duration of follow-up, time of day, and duration of fasting at blood collection. Conditional logistic regression models were used to calculate risk for prostate cancer associated with IGF-I concentration, overall and by various subgroups.
  
  
  RESULTS
  Circulating IGF-I concentration was associated with a significant increased risk for prostate cancer [OR for highest vs. lowest quartile, 1.69; 95% confidence interval (CI), 1.35-2.13; P(trend) = 0.0002]. This positive association did not differ according to duration of follow-up [ORs for highest vs. lowest quartile were 2.01 (1.35-2.99), 1.37 (0.94-2.00), and 1.80 (1.17-2.77) for cancers diagnosed <4, 4-7, and >7 years after blood collection, respectively (P(heterogeneity) = 0.77)] or by stage, grade, and age at diagnosis or age at blood collection (all subgroups P(heterogeneity) >0.05).
  
  
  CONCLUSIONS
  In this European population, high circulating IGF-I concentration is positively associated with risk for prostate cancer over the short and long term.
  
  
  CONCLUSIONS
  As IGF-I is the only potentially modifiable risk factor so far identified, research into the effects of reducing circulating IGF-I levels on subsequent prostate cancer risk is warranted.
authors: Cancer Epidemiology Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom. alison.price@ceu.ox.ac.uk
authors: Alison J
authors: AJ
authors: Price
authors: Naomi E
authors: NE
authors: Allen
authors: Paul N
authors: PN
authors: Appleby
authors: Francesca L
authors: FL
authors: Crowe
authors: Ruth C
authors: RC
authors: Travis
authors: Sarah J
authors: SJ
authors: Tipper
authors: Kim
authors: K
authors: Overvad
authors: Henning
authors: H
authors: Grønbæk
authors: Anne
authors: A
authors: Tjønneland
authors: Nina Føns
authors: NF
authors: Johnsen
authors: Sabina
authors: S
authors: Rinaldi
authors: Rudolf
authors: R
authors: Kaaks
authors: Annie
authors: A
authors: Lukanova
authors: Heiner
authors: H
authors: Boeing
authors: Krasimira
authors: K
authors: Aleksandrova
authors: Antonia
authors: A
authors: Trichopoulou
authors: Dimitrios
authors: D
authors: Trichopoulos
authors: George
authors: G
authors: Andarakis
authors: Domenico
authors: D
authors: Palli
authors: Vittorio
authors: V
authors: Krogh
authors: Rosario
authors: R
authors: Tumino
authors: Carlotta
authors: C
authors: Sacerdote
authors: H Bas
authors: HB
authors: Bueno-de-Mesquita
authors: Marcial V
authors: MV
authors: Argüelles
authors: Maria-José
authors: MJ
authors: Sánchez
authors: Maria-Dolores
authors: MD
authors: Chirlaque
authors: Aurelio
authors: A
authors: Barricarte
authors: Nerea
authors: N
authors: Larrañaga
authors: Carlos A
authors: CA
authors: González
authors: Pär
authors: P
authors: Stattin
authors: Mattias
authors: M
authors: Johansson
authors: Kay-Tee
authors: KT
authors: Khaw
authors: Nick
authors: N
authors: Wareham
authors: Marc
authors: M
authors: Gunter
authors: Elio
authors: E
authors: Riboli
authors: Timothy
authors: T
authors: Key
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000097:blood / Q000209:etiology*; D012306:Risk
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I