title: Serum levels of IGF-I and BRCA penetrance: a case control study in breast cancer families.
abstract: High serum levels of insulin-like growth factor I (IGF-I) are associated with an increased risk of sporadic breast cancer (BC). The aim of the present work is to evaluate the association between IGF-I and hereditary BC risk, using a case-control approach. The work represents an "ad interim" cross-sectional analysis of an ongoing study with a prospective design whose aim is to recruit a cohort of women belonging to high genetic risk families to test potential modulators of penetrance and prognosis. The odd of exposure to high serum IGF-I levels among women with a previous diagnosis of BC ("cases") was compared with the odd among unaffected "controls". The odds ratio (OR) and 95% confidence intervals (CIs) were estimated by unconditional logistic regression, controlling for confounders. We analysed 308 women (209 cases and 99 controls) at high genetic risk of BC. The adjusted OR of BC for the upper tertile of serum IGF-I versus the lowest one was 3.5 (95%CI 1.4-8.8). Excluding from the analysis 64 women under current Tamoxifen or GnRH analogues treatment, the adjusted OR of BC became 3.7 (95%CI 1.4-9.9). The association became stronger restricting the analysis to the 161 women (97 cases and 64 controls) with a proven BRCA mutation. If confirmed by a prospective approach, the association between IGF-I and familial BC will open further options for reducing BC risk in susceptible women.
authors: Etiological and Preventive Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. patrizia.pasanisi@istitutotumori.mi.it
authors: Patrizia
authors: P
authors: Pasanisi
authors: Eleonora
authors: E
authors: Bruno
authors: Elisabetta
authors: E
authors: Venturelli
authors: Siranoush
authors: S
authors: Manoukian
authors: Monica
authors: M
authors: Barile
authors: Bernard
authors: B
authors: Peissel
authors: Clelia
authors: C
authors: De Giacomi
authors: Bernardo
authors: B
authors: Bonanni
authors: Jacopo
authors: J
authors: Berrino
authors: Franco
authors: F
authors: Berrino
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019313:BRCA1 Protein / Q000235:genetics*; D024682:BRCA2 Protein / Q000235:genetics*; D001943:Breast Neoplasms / Q000097:blood* / Q000235:genetics*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D016017:Odds Ratio; D019683:Penetrance; D017698:Postmenopause; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D024682:BRCA2 Protein; C551750:BRCA2 protein, human; D007334:Insulin-Like Growth Factor I