title: Dietary patterns and risk of breast cancer.
abstract: BACKGROUND
  Evidence is emerging that prudent/healthy dietary patterns might be associated with a reduced risk of breast cancer.
  
  
  METHODS
  Using data from the prospective Melbourne Collaborative Cohort Study, we applied principal factor analysis to 124 foods and beverages to identify dietary patterns and estimated their association with breast cancer risk overall and by tumour characteristics using Cox regression.
  
  
  RESULTS
  During an average of 14.1 years of follow-up of 20 967 women participants, 815 invasive breast cancers were diagnosed. Among the four dietary factors that we identified, only that characterised by high consumption of fruit and salad was associated with a reduced risk, with stronger associations observed for tumours not expressing oestrogen (ER) and progesterone receptors (PR). Compared with women in the lowest quintile of the factor score, the hazard ratio for women in the highest quintile was 0.92 (95% confidence interval (CI)=0.70-1.21; test for trend, P=0.5) for ER-positive or PR-positive tumours and 0.48 (95% CI=0.26-0.86; test for trend, P=0.002) for ER-negative and PR-negative tumours (test for homogeneity, P=0.01).
  
  
  CONCLUSIONS
  Our study provides additional support for the hypothesis that a dietary pattern rich in fruit and salad might protect against invasive breast cancer and that the effect might be stronger for ER- and PR-negative tumours.
authors.affiliation: Cancer Epidemiology Centre, The Cancer Council Victoria, 100 Drummond Street, Carlton, Melbourne, Victoria 3053, Australia. laura.baglietto@cancervic.org.au
authors.forename: L
authors.initials: L
authors.lastname: Baglietto
authors.forename: K
authors.initials: K
authors.lastname: Krishnan
authors.forename: G
authors.initials: G
authors.lastname: Severi
authors.forename: A
authors.initials: A
authors.lastname: Hodge
authors.forename: M
authors.initials: M
authors.lastname: Brinkman
authors.forename: D R
authors.initials: DR
authors.lastname: English
authors.forename: C
authors.initials: C
authors.lastname: McLean
authors.forename: J L
authors.initials: JL
authors.lastname: Hopper
authors.forename: G G
authors.initials: GG
authors.lastname: Giles
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000378:metabolism; D004032:Diet; D005260:Female; D005500:Follow-Up Studies; D005638:Fruit; D006801:Humans; D008875:Middle Aged; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D012307:Risk Factors; D014675:Vegetables
chemical_list: D011960:Receptors, Estrogen; D011980:Receptors, Progesterone