Smoking and the risk of breast cancer among carriers of BRCA mutations.
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.
Ghadirian
Parviz
P
Epidemiology Research Unit, Centre Hospitalier del'Universite de Montreal Hotel-Dieu, Faculty of Medicine, Université de Montreal, Montreal, Quebec, Canada.
Lubinski
Jan
J
Lynch
Henry
H
Neuhausen
Susan L
SL
Weber
Barbara
B
Isaacs
Claudine
C
Baruch
Ruth-Gershoni
RG
Randall
Susan
S
Ainsworth
Peter
P
Friedman
Eitan
E
Freidman
Eitan
E
Horsman
Douglas
D
Tonin
Patricia
P
Foulkes
William D
WD
Tung
Nadine
N
Sun
Ping
P
Narod
Steven A
SA
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