title: Alcohol consumption and breast cancer risk among postmenopausal women following the cessation of hormone therapy use: the California Teachers Study.
abstract: BACKGROUND
  Alcohol consumption increases breast cancer risk, but its effect may be modified by hormone therapy (HT) use, such that exposure to both may be synergistic. Because many women stopped taking HT after mid-2002, it is important to quantify risks associated with alcohol consumption in the context of HT cessation, as these risks may be more relevant to cancer prevention efforts today.
  
  
  METHODS
  Among 40,680 eligible postmenopausal California Teachers Study cohort participants, 660 were diagnosed with invasive breast cancer before 2010. Multivariate Cox proportional hazards regression models were used to estimate relative risks (RR) and 95% confidence intervals (CI).
  
  
  RESULTS
  Increased breast cancer risk associated with alcohol consumption was observed among postmenopausal women who were current HT users [RR, 1.60; 95% confidence interval (CI), 1.13-2.26 and RR, 2.11; 95% CI, 1.41-3.15 for <20 and ≥20 g/d of alcohol], with risks being similar by HT preparation. Alcohol did not increase risk among women who had stopped using HT within 3 years or 3 to 4 years before completing the follow-up questionnaire or in the more distant past. Results were similar for estrogen receptor positive (ER+) and ER+PR+ progesterone receptors positive (PR+) tumors; while power was limited, no increase in risk was observed for ER- tumors.
  
  
  CONCLUSIONS
  Following the cessation of HT use, alcohol consumption is not significantly associated with breast cancer risk, although a nonsignificant increased risk was observed among women who never used HT.
  
  
  CONCLUSIONS
  Our findings confirm that concurrent exposure to HT and alcohol has a substantial adverse impact on breast cancer risk. However, after HT cessation, this risk is reduced.
authors: Cancer Prevention Institute of California, 2201 Walnut Ave., Suite 300, Fremont, CA 94538. pam@cpic.org
authors: Pamela L
authors: PL
authors: Horn-Ross
authors: Alison J
authors: AJ
authors: Canchola
authors: Leslie
authors: L
authors: Bernstein
authors: Christina A
authors: CA
authors: Clarke
authors: James V
authors: JV
authors: Lacey
authors: Susan L
authors: SL
authors: Neuhausen
authors: Peggy
authors: P
authors: Reynolds
authors: Giske
authors: G
authors: Ursin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology*; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D015914:Estrogen Replacement Therapy / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires