title: Plasma IGF-1 and IGFBP-3 may be imprecise surrogates for breast concentrations: an analysis of healthy women.
abstract: We investigated insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-3 concentrations in histologically normal breast tissues and assessed their association with plasma concentrations, and breast cancer risk factors. IGF-1 and IGFBP-3 were assessed in plasma and breast tissues of 90 women with no history of any cancer and undergoing reduction mammoplasty. Pearson correlations and ANOVAs were used to describe plasma-breast associations and biomarker differences by breast cancer risk factors, respectively. Multivariable regression models were used to determine associations between risk factors, and breast IGF-1 and IGFBP-3. The mean age of the study sample was 37.3 years, 58 % were white, and generally these women were obese (mean BMI = 30.8 kg/m(2)). We observed no plasma-breast correlation for IGF-1, IGFBP-3, or IGF-1/IGFBP-3 (r = -0.08, r = 0.14, and r = 0.03, respectively; p-values >0.05). Through age- and BMI-adjusted analysis, BMI and years of oral contraceptive (OC) use were inversely associated with breast IGF-1 (p-values = 0.02 and 0.003, respectively) and age was associated with breast IGFBP-3 (p = 0.01), while breast IGF-1/IGFBP-3 was higher in blacks than whites (1.08 vs. 0.68, p = 0.04) and associated with age and BMI (p-values = 0.03 and 0.002, respectively). In multivariable-adjusted models, some breast cancer risk factors studied herein explained 24, 10, and 15 % of the variation in breast IGF-1, IGFBP-3, and IGF-1/IGFBP-3, respectively. While reasons for the lack of plasma-breast hormone correlations in these cancer-free women are unknown, several factors were shown to be associated with breast concentrations. The lack of correlation between blood and tissue IGF-1 and IGFBP-3 suggests that studies of breast cancer risk assessing blood IGF-1 and IGFBP-3 may have important limitations in understanding their role in breast carcinogenesis.
authors: Division of Population Sciences, The Ohio State University Comprehensive Cancer Center, 1590 North High Street, Suite 525, Columbus, OH 43201, USA. Adana.Llanos@osumc.edu
authors: Adana A
authors: AA
authors: Llanos
authors: Theodore M
authors: TM
authors: Brasky
authors: Ramona G
authors: RG
authors: Dumitrescu
authors: Catalin
authors: C
authors: Marian
authors: Kepher H
authors: KH
authors: Makambi
authors: Bhaskar V S
authors: BV
authors: Kallakury
authors: Scott L
authors: SL
authors: Spear
authors: David J
authors: DJ
authors: Perry
authors: Rafael J
authors: RJ
authors: Convit
authors: Mary E
authors: ME
authors: Platek
authors: Lucile L
authors: LL
authors: Adams-Campbell
authors: Jo L
authors: JL
authors: Freudenheim
authors: Peter G
authors: PG
authors: Shields
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006262:Health; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D016014:Linear Models; D016462:Mammaplasty; D042361:Mammary Glands, Human / Q000378:metabolism* / Q000601:surgery; D008875:Middle Aged; D015999:Multivariate Analysis; D012016:Reference Values; D012307:Risk Factors
chemical_list: C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I