title: Lifetime alcohol consumption and breast cancer: a case-control study in Finland.
abstract: OBJECTIVE
  To study the association between lifetime alcohol consumption and the risk of breast cancer.
  
  
  METHODS
  A case-control study carried out in eastern Finland. Information about alcohol consumption was obtained by two methods: a self-administered food frequency questionnaire (FFQ) including alcohol consumption during the previous 12 months, and a lifetime alcohol consumption questionnaire (AQ) which was administered by the study nurse.
  
  
  METHODS
  The study consisted of 301 breast cancer cases (25-75 years old) and 443 population controls.
  
  
  RESULTS
  The subjects reported higher current alcohol consumption in the AQ compared to the FFQ. According to the AQ, premenopausal cases consumed on average 28 g and controls 24 g alcohol week(-1); in postmenopausal women the values were 15 and 14 g, respectively. About 30% of premenopausal and 60% of postmenopausal women were classified as non-drinkers. The correlation for current alcohol consumption between the FFQ and the AQ was 0.80 in premenopausal women but only 0.40 in postmenopausal women. Current alcohol consumption seemed to influence the reporting of total lifetime alcohol consumption. Current alcohol consumption was not associated with the risk of breast cancer either in premenopausal or postmenopausal women; neither were associations found between alcohol consumption at age of first use, use before the age of 30, or total lifetime alcohol consumption and the risk of breast cancer.
  
  
  CONCLUSIONS
  On average, one to three drinks per week did not increase the risk of breast cancer in this study. Consumption levels were, however, too low to exclude increased risk with high regular consumption. Further research is necessary on lifetime alcohol consumption.
authors.affiliation: National Public Health Institute, Department of Nutrition, Helsinki, Finland. satu.mannisto@ktl.fi
authors.forename: S
authors.initials: S
authors.lastname: Männistö
authors.forename: M
authors.initials: M
authors.lastname: Virtanen
authors.forename: V
authors.initials: V
authors.lastname: Kataja
authors.forename: M
authors.initials: M
authors.lastname: Uusitupa
authors.forename: P
authors.initials: P
authors.lastname: Pietinen
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects* / Q000453:epidemiology*; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013997:Time Factors