title: Smoking and alcohol consumption in relation to risk of triple-negative breast cancer in a cohort of postmenopausal women.
abstract: OBJECTIVE
  Little is known about the risk factors for triple-negative breast cancer (TNBC), which has a worse prognosis compared to hormone receptor-positive breast cancer. We examined the association of smoking and alcohol intake with TNBC and estrogen receptor-positive (ER+) breast cancer.
  
  
  METHODS
  Among 148,030 women enrolled in the Women's Health Initiative, 300 TNBC cases and 2,479 ER+ cases were identified over a median of 8.0 years of follow-up. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI).
  
  
  RESULTS
  Cigarette smoking was not associated with TNBC, whereas drinkers had reduced risk compared to never drinkers. In contrast, both exposures showed slight positive associations with ER+ breast cancer: for women with ≥ 40 pack-years of smoking, the HR was 1.24, 95% CI 1.06-1.44; for women consuming ≥ 7 servings of alcohol per week, the HR was 1.26, 95% CI 1.06-1.50. Intakes of wine and hard liquor were also significantly positively associated with ER+ breast cancer.
  
  
  CONCLUSIONS
  These findings from a large cohort of postmenopausal women suggest that smoking and alcohol consumption are not associated with increased risk of TNBC, but may be modestly associated with increased risk of ER+ breast cancer.
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA. Geoffrey.Kabat@einstein.yu.edu
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Kabat
authors.forename: Mimi
authors.initials: M
authors.lastname: Kim
authors.forename: Amanda I
authors.initials: AI
authors.lastname: Phipps
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Li
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Messina
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.forename: Lewis
authors.initials: L
authors.lastname: Kuller
authors.forename: Michael S
authors.initials: MS
authors.lastname: Simon
authors.forename: Shagufta
authors.initials: S
authors.lastname: Yasmeen
authors.forename: Sylvia
authors.initials: S
authors.lastname: Wassertheil-Smoller
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rohan
mesh_terms: D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology*; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000378:metabolism / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D011379:Prognosis; D011960:Receptors, Estrogen / Q000378:metabolism; D012307:Risk Factors; D012907:Smoking
chemical_list: D011960:Receptors, Estrogen