title: Smoking and the risk of breast cancer among carriers of BRCA mutations.
abstract: The effect of cigarette smoking on the risk of breast cancer is controversial, although most studies show little or no effect. It has been suggested that smoking may reduce the risk of developing hereditary breast cancer. We completed a case-control study on 1,097 women with breast cancer who were BRCA1 or BRCA2 mutation carriers and 1,097 age-matched controls with a mutation in the same gene but without breast cancer. There were no statistically significant differences between the cases and controls in terms of the number of current and ex-smokers (41.2% and 40.4%, respectively) or the age at smoking commencement (18.2 years and 18.5 years, respectively). There were no statistically significant differences between cases and controls regarding beginning smoking within 5 years of menarche (OR = 1.03; 95% CI 0.83 to l.28) or before the first pregnancy (OR = 1.09; 95% CI = 0.90 to 1.33). In conclusion, contrary to our previous report, smoking does not appear to be a risk factor for breast cancer among carriers of BRCA mutations.
authors.affiliation: Epidemiology Research Unit, Centre Hospitalier del'Universite de Montreal Hotel-Dieu, Faculty of Medicine, Université de Montreal, Montreal, Quebec, Canada.
authors.forename: Parviz
authors.initials: P
authors.lastname: Ghadirian
authors.forename: Jan
authors.initials: J
authors.lastname: Lubinski
authors.forename: Henry
authors.initials: H
authors.lastname: Lynch
authors.forename: Susan L
authors.initials: SL
authors.lastname: Neuhausen
authors.forename: Barbara
authors.initials: B
authors.lastname: Weber
authors.forename: Claudine
authors.initials: C
authors.lastname: Isaacs
authors.forename: Ruth-Gershoni
authors.initials: RG
authors.lastname: Baruch
authors.forename: Susan
authors.initials: S
authors.lastname: Randall
authors.forename: Peter
authors.initials: P
authors.lastname: Ainsworth
authors.forename: Eitan
authors.initials: E
authors.lastname: Friedman
authors.forename: Eitan
authors.initials: E
authors.lastname: Freidman
authors.forename: Douglas
authors.initials: D
authors.lastname: Horsman
authors.forename: Patricia
authors.initials: P
authors.lastname: Tonin
authors.forename: William D
authors.initials: WD
authors.lastname: Foulkes
authors.forename: Nadine
authors.initials: N
authors.lastname: Tung
authors.forename: Ping
authors.initials: P
authors.lastname: Sun
authors.forename: Steven A
authors.initials: SA
authors.lastname: Narod
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics*; D016022:Case-Control Studies; D004252:DNA Mutational Analysis; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D006579:Heterozygote; D006801:Humans; D008572:Menarche; D008875:Middle Aged; D009154:Mutation; D016017:Odds Ratio; D011247:Pregnancy; D012307:Risk Factors; D012907:Smoking