title: The contribution of risk factors to the higher incidence of invasive and in situ breast cancers in women with higher levels of education in the European prospective investigation into cancer and nutrition.
abstract: The authors investigated the role of known risk factors in educational differences in breast cancer incidence. Analyses were based on the European Prospective Investigation Into Cancer and Nutrition and included 242,095 women, 433 cases of in situ breast cancer, and 4,469 cases of invasive breast cancer. Reproductive history (age at first full-term pregnancy and parity), exposure to endogenous and exogenous hormones, height, and health behaviors were accounted for in the analyses. Relative indices of inequality (RII) for education were estimated using Cox regression models. A higher risk of invasive breast cancer was found among women with higher levels of education (RII = 1.22, 95% confidence interval (CI): 1.09, 1.37). This association was not observed among nulliparous women (RII = 1.13, 95% CI: 0.84, 1.52). Inequalities in breast cancer incidence decreased substantially after adjusting for reproductive history (RII = 1.11, 95% CI: 0.98, 1.25), with most of the association being explained by age at first full-term pregnancy. Each other risk factor explained a small additional part of the inequalities in breast cancer incidence. Height accounted for most of the remaining differences in incidence. After adjusting for all known risk factors, the authors found no association between education level and risk of invasive breast cancer. Inequalities in incidence were more pronounced for in situ breast cancer, and those inequalities remained after adjustment for all known risk factors (RII = 1.61, 95% CI: 1.07, 2.41), especially among nulliparous women.
authors.affiliation: National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands. gwenn.menvielle@inserm.fr
authors.forename: Gwenn
authors.initials: G
authors.lastname: Menvielle
authors.forename: Anton E
authors.initials: AE
authors.lastname: Kunst
authors.forename: Carla H
authors.initials: CH
authors.lastname: van Gils
authors.forename: Petra H
authors.initials: PH
authors.lastname: Peeters
authors.forename: Hendriek
authors.initials: H
authors.lastname: Boshuizen
authors.forename: Kim
authors.initials: K
authors.lastname: Overvad
authors.forename: Anja
authors.initials: A
authors.lastname: Olsen
authors.forename: Anne
authors.initials: A
authors.lastname: Tjonneland
authors.forename: Silke
authors.initials: S
authors.lastname: Hermann
authors.forename: Rudolf
authors.initials: R
authors.lastname: Kaaks
authors.forename: Manuela M
authors.initials: MM
authors.lastname: Bergmann
authors.forename: Anne-Kathrin
authors.initials: AK
authors.lastname: Illner
authors.forename: Pagona
authors.initials: P
authors.lastname: Lagiou
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Trichopoulos
authors.forename: Antonia
authors.initials: A
authors.lastname: Trichopoulou
authors.forename: Domenico
authors.initials: D
authors.lastname: Palli
authors.forename: Franco
authors.initials: F
authors.lastname: Berrino
authors.forename: Amelia
authors.initials: A
authors.lastname: Mattiello
authors.forename: Rosario
authors.initials: R
authors.lastname: Tumino
authors.forename: Carlotta
authors.initials: C
authors.lastname: Sacerdote
authors.forename: Anne
authors.initials: A
authors.lastname: May
authors.forename: Evelyn
authors.initials: E
authors.lastname: Monninkhof
authors.forename: Tonje
authors.initials: T
authors.lastname: Braaten
authors.forename: Eiliv
authors.initials: E
authors.lastname: Lund
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Quirós
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Duell
authors.forename: Maria-José
authors.initials: MJ
authors.lastname: Sánchez
authors.forename: Carmen
authors.initials: C
authors.lastname: Navarro
authors.forename: Eva
authors.initials: E
authors.lastname: Ardanaz
authors.forename: Signe
authors.initials: S
authors.lastname: Borgquist
authors.forename: Jonas
authors.initials: J
authors.lastname: Manjer
authors.forename: Kay Tee
authors.initials: KT
authors.lastname: Khaw
authors.forename: Naomi E
authors.initials: NE
authors.lastname: Allen
authors.forename: Gillian K
authors.initials: GK
authors.lastname: Reeves
authors.forename: Véronique
authors.initials: V
authors.lastname: Chajes
authors.forename: Sabina
authors.initials: S
authors.lastname: Rinaldi
authors.forename: Nadia
authors.initials: N
authors.lastname: Slimani
authors.forename: Valentina
authors.initials: V
authors.lastname: Gallo
authors.forename: Paolo
authors.initials: P
authors.lastname: Vineis
authors.forename: Elio
authors.initials: E
authors.lastname: Riboli
authors.forename: H Bas
authors.initials: HB
authors.lastname: Bueno-de-Mesquita
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D004522:Educational Status; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009749:Nutrition Surveys / Q000379:methods*; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D017584:Reproductive History; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors