Breast cancer risk in relation to urinary and serum biomarkers of phytoestrogen exposure in the European Prospective into Cancer-Norfolk cohort study.

TitleBreast cancer risk in relation to urinary and serum biomarkers of phytoestrogen exposure in the European Prospective into Cancer-Norfolk cohort study.
Publication TypeJournal Article
Year of Publication2008
AuthorsWard, H, Chapelais, G, Kuhnle, GGC, Luben, R, Khaw, K-T, Bingham, S
Corporate Authors
JournalBreast Cancer Res
Volume10
Issue2
PaginationR32
Date Published2008
ISSN1465-542X
KeywordsAged, Biomarkers, Tumor, Breast Neoplasms, Cohort Studies, Female, Health Status, Humans, Life Style, Middle Aged, Phytoestrogens, Prospective Studies, Risk Assessment, Risk Factors, Surveys and Questionnaires
Abstract

INTRODUCTION: Phytoestrogens are a group of compounds found in plants that structurally resemble the hormone oestradiol, and thus have the potential to act as oestrogen agonists or antagonists. Their potential effects may alter the risk of breast cancer, but only a limited range of phytoestrogens has been examined in prospective cohort studies.METHODS: Serum and urine samples from 237 incident breast cancer cases and 952 control individuals (aged 45 to 75 years) in the European Prospective into Cancer-Norfolk cohort were analysed for seven phytoestrogens (daidzein, enterodiol, enterolactone, genistein, glycitein, o-desmethylangolensin, and equol) using liquid chromatography/mass spectrometry. Data on participants' diet, demographics, anthropometrics, and medical history were collected upon recruitment. All models were adjusted for weight, fat and energy intake, family history of breast cancer, social class, analytical batch, and factors related to oestrogen exposure.RESULTS: Urinary or serum phytoestrogens were not associated with protection from breast cancer in the European Prospective into Cancer-Norfolk cohort. Breast cancer risk was marginally increased with higher levels of total urinary isoflavones (odds ratio = 1.08 (95% confidence interval = 1.00 to 1.16), P = 0.055); among those with oestrogen receptor-positive tumours, the risk of breast cancer was increased with higher levels of urinary equol (odds ratio = 1.07 (95% confidence interval = 1.01 to 1.12), P = 0.013).CONCLUSION: There was limited evidence of an association between phytoestrogen biomarkers and breast cancer risk in the present study. There was no indication of decreased likelihood of breast cancer with higher levels of phytoestrogen biomarkers, but the observation that some phytoestrogen biomarkers may be associated with greater risk of breast cancer warrants further study with greater statistical power.

DOI10.1186/bcr1995
Alternate JournalBreast Cancer Res.
Citation Key10.1186/bcr1995
PubMed ID18419813
PubMed Central IDPMC2397534
Grant ListG0401527 / / Medical Research Council / United Kingdom