title: Moderate alcohol consumption during adult life, drinking patterns, and breast cancer risk.
abstract: BACKGROUND
  Multiple studies have linked alcohol consumption to breast cancer risk, but the risk of lower levels of consumption has not been well quantified. In addition, the role of drinking patterns (ie, frequency of drinking and "binge" drinking) and consumption at different times of adult life are not well understood.
  
  
  OBJECTIVE
  To evaluate the association of breast cancer with alcohol consumption during adult life, including quantity, frequency, and age at consumption.
  
  
  METHODS
  Prospective observational study of 105,986 women enrolled in the Nurses' Health Study followed up from 1980 until 2008 with an early adult alcohol assessment and 8 updated alcohol assessments.
  
  
  METHODS
  Relative risks of developing invasive breast cancer.
  
  
  RESULTS
  During 2.4 million person-years of follow-up, 7690 cases of invasive breast cancer were diagnosed. Increasing alcohol consumption was associated with increased breast cancer risk that was statistically significant at levels as low as 5.0 to 9.9 g per day, equivalent to 3 to 6 drinks per week (relative risk, 1.15; 95% CI, 1.06-1.24; 333 cases/100,000 person-years). Binge drinking, but not frequency of drinking, was associated with breast cancer risk after controlling for cumulative alcohol intake. Alcohol intake both earlier and later in adult life was independently associated with risk.
  
  
  CONCLUSIONS
  Low levels of alcohol consumption were associated with a small increase in breast cancer risk, with the most consistent measure being cumulative alcohol intake throughout adult life. Alcohol intake both earlier and later in adult life was independently associated with risk.
authors: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA. wendy.chen@channing.harvard.edu
authors: Wendy Y
authors: WY
authors: Chen
authors: Bernard
authors: B
authors: Rosner
authors: Susan E
authors: SE
authors: Hankinson
authors: Graham A
authors: GA
authors: Colditz
authors: Walter C
authors: WC
authors: Willett
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000428:Alcohol Drinking; D001943:Breast Neoplasms / Q000453:epidemiology*; D000697:Central Nervous System Stimulants / Q000506:poisoning*; D004305:Dose-Response Relationship, Drug; D004967:Estrogens / Q000097:blood; D000431:Ethanol / Q000506:poisoning*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D011960:Receptors, Estrogen; D018570:Risk Assessment; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D004967:Estrogens; D011960:Receptors, Estrogen; D000431:Ethanol