title: A prospective study of serum insulin-like growth factor-I (IGF-I), IGF-II, IGF-binding protein-3 and breast cancer risk.
abstract: The associations between serum concentrations of insulin-like growth factor-I (IGF-I), IGF-II and IGF-binding proteins (IGFBP)-3 and risk of breast cancer were investigated in a nested case-control study involving 117 cases (70 premenopausal and 47 postmenopausal at blood collection) and 350 matched controls within a cohort of women from the island of Guernsey, UK. Women using exogenous hormones at the time of blood collection were excluded. Premenopausal women in the top vs bottom third of serum IGF-I concentration had a nonsignificantly increased risk for breast cancer after adjustment for IGFBP-3 (odds ratio (OR) 1.71; 95% confidence interval (CI): 0.74-3.95; test for linear trend, P=0.21). Serum IGFBP-3 was associated with a reduction in risk in premenopausal women after adjustment for IGF-I (top third vs the bottom third: OR 0.49; 95% CI: 0.21-1.12, P for trend=0.07). Neither IGF-I nor IGFBP-3 was associated with risk in postmenopausal women and serum IGF-II concentration was not associated with risk in pre- or postmenopausal women. These data are compatible with the hypothesis that premenopausal women with a relatively high circulating concentration of IGF-I and low IGFBP-3 are at an increased risk of developing breast cancer.
authors.affiliation: Cancer Research UK Epidemiology Unit, University of Oxford, Radcliffe Infirmary, Oxford OX2 6HE, UK.
authors.forename: N E
authors.initials: NE
authors.lastname: Allen
authors.forename: A W
authors.initials: AW
authors.lastname: Roddam
authors.forename: D S
authors.initials: DS
authors.lastname: Allen
authors.forename: I S
authors.initials: IS
authors.lastname: Fentiman
authors.forename: I
authors.initials: I
authors.lastname: Dos Santos Silva
authors.forename: J
authors.initials: J
authors.lastname: Peto
authors.forename: J M P
authors.initials: JM
authors.lastname: Holly
authors.forename: T J
authors.initials: TJ
authors.lastname: Key
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000209:etiology* / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007335:Insulin-Like Growth Factor II / Q000032:analysis*; D008875:Middle Aged; D017698:Postmenopause; D017697:Premenopause; D011446:Prospective Studies; D012307:Risk Factors; D006113:United Kingdom
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II