title: Breast, colorectal, and prostate cancer risk in the European Prospective Investigation into Cancer and Nutrition-Norfolk in relation to phytoestrogen intake derived from an improved database.
abstract: BACKGROUND
  The characterization of phytoestrogen intake and cancer risk has been hindered by the absence of accurate dietary phytoestrogen values.
  
  
  OBJECTIVE
  We examined the risk of breast, colorectal, and prostate cancers relative to phytoestrogen intake on the basis of a comprehensive database.
  
  
  METHODS
  Demographic and anthropometric characteristics, a medical history, and 7-d records of diet were collected prospectively from participants (aged 40-79 y) in the European Prospective Investigation into Cancer and Nutrition-Norfolk (EPIC-Norfolk). Five hundred nine food items were analyzed by liquid chromatography-mass spectrometry/mass spectrometry, and (13)C(3)-labeled internal standards were analyzed for isoflavones (genistein, daidzein, glycitein, biochanin A, and formononetin), lignans (secoisolariciresinol and matairesinol), and enterolignans from gut microbial metabolism in animal food sources (equol and enterolactone). From the direct analysis, values for 10,708 foods were calculated. Odds ratios (ORs) for breast (244 cases, 941 controls), colorectal (221 cases, 886 controls), and prostate (204 cases, 812 controls) cancers were calculated relative to phytoestrogen intake.
  
  
  RESULTS
  Phytoestrogen intake was not associated with breast cancer among women or colorectal cancer among men. Among women, colorectal cancer risk was inversely associated with enterolactone (OR: 0.33; 95% CI: 0.14, 0.74) and total enterolignans (OR: 0.32; 95% CI: 0.13, 0.79), with a positive trend detected for secoisolariciresinol (OR: 1.60; 95% CI: 0.96, 2.69). A positive trend between enterolignan intake and prostate cancer risk (OR: 1.27; 95% CI: 0.97, 1.66) was attenuated after adjustment for dairy intake (OR: 1.19; 95% CI: 0.77, 1.82).
  
  
  CONCLUSIONS
  Dietary phytoestrogens may contribute to the risk of colorectal cancer among women and prostate cancer among men.
authors.affiliation: MRC Centre for Nutrition and Cancer, Department of Public Health and Primary Care, Strangeways Research Laboratory, Wort's Causeway, Cambridge, United Kingdom. heather.ward@srl.cam.ac.uk
authors.forename: Heather A
authors.initials: HA
authors.lastname: Ward
authors.forename: Gunter G C
authors.initials: GG
authors.lastname: Kuhnle
authors.forename: Angela A
authors.initials: AA
authors.lastname: Mulligan
authors.forename: Marleen A H
authors.initials: MA
authors.lastname: Lentjes
authors.forename: Robert N
authors.initials: RN
authors.lastname: Luben
authors.forename: Kay-Tee
authors.initials: KT
authors.lastname: Khaw
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D015994:Incidence; D007529:Isoflavones / Q000008:administration & dosage / Q000009:adverse effects; D017705:Lignans / Q000008:administration & dosage / Q000009:adverse effects; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D048789:Phytoestrogens / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology*; D012307:Risk Factors; D021241:Spectrometry, Mass, Electrospray Ionization; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D007529:Isoflavones; D017705:Lignans; D048789:Phytoestrogens