Abstract | BACKGROUND: Studies conducted in Asian populations have suggested that high consumption of soy-based foods that are rich in isoflavone phytoestrogens is associated with a reduced risk of breast cancer. However, the potential associations of other dietary phytoestrogens--i.e., the lignans or their bioactive metabolites, the enterolignans--with the risk of breast cancer are unclear. METHODS: We prospectively examined associations between the risk of postmenopausal invasive breast cancer and dietary intakes of four plant lignans ( pinoresinol, lariciresinol, secoisolariciresinol, and matairesinol) and estimated exposure to two enterolignans ( enterodiol and enterolactone), as measured with a self-administered diet history questionnaire, among 58,049 postmenopausal French women who were not taking soy isoflavone supplements. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox proportional hazards regression models. Analyses were further stratified by the combined estrogen and progesterone receptor (ER/PR) status of the tumors. Statistical tests were two-sided. RESULTS: During 383,425 person-years of follow-up (median follow-up, 7.7 years), 1469 cases of breast cancer were diagnosed. Compared with women in the lowest intake quartiles, those in the highest quartile of total lignan intake (>1395 microg/day) had a reduced risk of breast cancer (RR = 0.83, 95% CI = 0.71 to 0.95, P(trend) = .02, 376 versus 411 cases per 100,000 person-years), as did those in the highest quartile of lariciresinol intake (RR = 0.82, 95% CI = 0.71 to 0.95, P(trend) = .01). The inverse associations between phytoestrogen intakes and postmenopausal breast cancer risk were limited to ER- and PR-positive disease (e.g., RR for highest versus lowest quartiles of total plant lignan intake = 0.72, 95% CI = 0.58 to 0.88, P(trend) = .01, 174 versus 214 cases per 100,000 person-years, and RR for highest versus lowest quartiles of total enterolignan level = 0.77, 95% CI = 0.62 to 0.95, P(trend) = .01, 164 versus 204 cases per 100,000 person-years). CONCLUSIONS: High dietary intakes of plant lignans and high exposure to enterolignans were associated with reduced risks of ER- and PR-positive postmenopausal breast cancer in a Western population that does not consume a diet rich in soy.
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Authors | Marina S Touillaud, Anne C M Thiébaut, Agnès Fournier, Maryvonne Niravong, Marie-Christine Boutron-Ruault, Françoise Clavel-Chapelon |
Journal | Journal of the National Cancer Institute
(J Natl Cancer Inst)
Vol. 99
Issue 6
Pg. 475-86
(Mar 21 2007)
ISSN: 1460-2105 [Electronic] United States |
PMID | 17374837
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Lignans
- Receptors, Estrogen
- Receptors, Progesterone
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Topics |
- Adult
- Aged
- Breast Neoplasms
(chemistry, prevention & control)
- Carcinoma, Ductal, Breast
(prevention & control)
- Diet Surveys
- Feeding Behavior
- Female
- Follow-Up Studies
- France
- Humans
- Lignans
(administration & dosage)
- Middle Aged
- Multivariate Analysis
- Odds Ratio
- Postmenopause
- Proportional Hazards Models
- Prospective Studies
- Receptors, Estrogen
(analysis)
- Receptors, Progesterone
(analysis)
- Reproducibility of Results
- Research Design
- Risk Assessment
- Surveys and Questionnaires
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