title: Active and passive cigarette smoking and breast cancer risk: results from the EPIC cohort.
abstract: Recent cohort studies suggest that increased breast cancer risks were associated with longer smoking duration, higher pack-years and a dose-response relationship with increasing pack-years of smoking between menarche and first full-term pregnancy (FFTP). Studies with comprehensive quantitative life-time measures of passive smoking suggest an association between passive smoking dose and breast cancer risk. We conducted a study within the European Prospective Investigation into Cancer and Nutrition to examine the association between passive and active smoking and risk of invasive breast cancer and possible effect modification by known breast cancer risk factors. Among the 322,988 women eligible for the study, 9,822 developed breast cancer (183,608 women with passive smoking information including 6,264 cases). When compared to women who never smoked and were not being exposed to passive smoking at home or work at the time of study registration, current, former and currently exposed passive smokers were at increased risk of breast cancer (hazard ratios (HR) [95% confidence interval (CI)] 1.16 [1.05-1.28], 1.14 [1.04-1.25] and 1.10 [1.01-1.20], respectively). Analyses exploring associations in different periods of life showed the most important increase in risk with pack-years from menarche to FFTP (1.73 [1.29-2.32] for every increase of 20 pack-years) while pack-years smoked after menopause were associated with a significant decrease in breast cancer risk (HR = 0.53, 95% CI: 0.34-0.82 for every increase of 20 pack-years). Our results provide an important replication, in the largest cohort to date, that smoking (passively or actively) increases breast cancer risk and that smoking between menarche and FFTP is particularly deleterious.
authors.affiliation: Inserm U1018, Centre for Research in Epidemiology and Population Health (CESP), Institut Gustave Roussy, Villejuif, France; Paris South University, Villejuif, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Dossus
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Boutron-Ruault
authors.forename: Rudolf
authors.initials: R
authors.lastname: Kaaks
authors.forename: Inger T
authors.initials: IT
authors.lastname: Gram
authors.forename: Alice
authors.initials: A
authors.lastname: Vilier
authors.forename: Béatrice
authors.initials: B
authors.lastname: Fervers
authors.forename: Jonas
authors.initials: J
authors.lastname: Manjer
authors.forename: Anne
authors.initials: A
authors.lastname: Tjonneland
authors.forename: Anja
authors.initials: A
authors.lastname: Olsen
authors.forename: Kim
authors.initials: K
authors.lastname: Overvad
authors.forename: Jenny
authors.initials: J
authors.lastname: Chang-Claude
authors.forename: Heiner
authors.initials: H
authors.lastname: Boeing
authors.forename: Annika
authors.initials: A
authors.lastname: Steffen
authors.forename: Antonia
authors.initials: A
authors.lastname: Trichopoulou
authors.forename: Pagona
authors.initials: P
authors.lastname: Lagiou
authors.forename: Maria
authors.initials: M
authors.lastname: Sarantopoulou
authors.forename: Domenico
authors.initials: D
authors.lastname: Palli
authors.forename: Franco
authors.initials: F
authors.lastname: Berrino
authors.forename: Rosario
authors.initials: R
authors.lastname: Tumino
authors.forename: Paolo
authors.initials: P
authors.lastname: Vineis
authors.forename: Amalia
authors.initials: A
authors.lastname: Mattiello
authors.forename: H Bas
authors.initials: HB
authors.lastname: Bueno-de-Mesquita
authors.forename: Franzel J B
authors.initials: FJ
authors.lastname: van Duijnhoven
authors.forename: Marieke F
authors.initials: MF
authors.lastname: Bakker
authors.forename: Petra Hm
authors.initials: PH
authors.lastname: Peeters
authors.forename: Elisabete
authors.initials: E
authors.lastname: Weiderpass
authors.forename: Eivind
authors.initials: E
authors.lastname: Bjerkaas
authors.forename: Tonje
authors.initials: T
authors.lastname: Braaten
authors.forename: Virginia
authors.initials: V
authors.lastname: Menéndez
authors.forename: Antonio
authors.initials: A
authors.lastname: Agudo
authors.forename: Maria-Jose
authors.initials: MJ
authors.lastname: Sanchez
authors.forename: Pilar
authors.initials: P
authors.lastname: Amiano
authors.forename: Maria-Jose
authors.initials: MJ
authors.lastname: Tormo
authors.forename: Aurelio
authors.initials: A
authors.lastname: Barricarte
authors.forename: Salma
authors.initials: S
authors.lastname: Butt
authors.forename: Kay-Tee
authors.initials: KT
authors.lastname: Khaw
authors.forename: Nicholas
authors.initials: N
authors.lastname: Wareham
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Key
authors.forename: Ruth C
authors.initials: RC
authors.lastname: Travis
authors.forename: Sabina
authors.initials: S
authors.lastname: Rinaldi
authors.forename: Valerie
authors.initials: V
authors.lastname: McCormack
authors.forename: Isabelle
authors.initials: I
authors.lastname: Romieu
authors.forename: David G
authors.initials: DG
authors.lastname: Cox
authors.forename: Teresa
authors.initials: T
authors.lastname: Norat
authors.forename: Elio
authors.initials: E
authors.lastname: Riboli
authors.forename: Françoise
authors.initials: F
authors.lastname: Clavel-Chapelon
mesh_terms: D001943:Breast Neoplasms / Q000139:chemically induced / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D015994:Incidence; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution
keywords: breast cancer; prospective; second-hand smoke; tobacco smoke