Serum isoflavones and lignans and odds of breast cancer in pre- and postmenopausal Chinese women.

Isoflavones and lignans are phytoestrogens present in plant-based foods, which have a potential preventive effect on breast carcinogenesis. The effects of phytoestrogens on breast cancer may differ according to the hormonal environment. This case-control study aimed to investigate the association between serum phytoestrogens and odds of breast cancer among Chinese pre- and postmenopausal women. A total of 792 cases and 813 age-matched controls were included. Serum isoflavone (daidzein, genistein, glycitein, equol, and formononetin) and lignan (enterodiol and enterolactone) concentrations were measured using a liquid chromatography-tandem mass spectrometry method. Significant inverse associations were found between serum total soy isoflavone precursors, daidzein, genistein, formononetin, total lignans, enterodiol, enterolactone, and the odds of breast cancer in premenopausal but not postmenopausal women. For premenopausal women, the adjusted odds ratios (95% confidence intervals) for the highest versus the lowest serum concentration groups were 0.60 (0.41-0.87) for total soy isoflavones precursors, 0.64 (0.44-0.93) for daidzein, 0.62 (0.43-0.90) for genistein, 0.49 (0.35-0.68) for formononetin, 0.38 (0.25-0.57) for total lignans, 0.49 (0.33-0.73) for enterodiol, and 0.49 (0.33-0.74) for enterolactone. However, the interaction between serum phytoestrogens and menopausal status on odds of breast cancer was statistically significant only for daidzein. No significant association was found between serum equol or gycitein and the odds of breast cancer among either pre- or postmenopausal women. Higher levels of certain serum isoflavones and lignans were associated with reduced odds of breast cancer in premenopausal women, but the interaction was statistically significant only for daidzein.

Feng XL ，Ho SC ，Zhan XX ，Zuo LS ，Mo XF ，Zhang X ，Abulimiti A ，Huang CY ，Zhang CX ... -  《-》

Plasma phytoestrogens and subsequent breast cancer risk.

Verheus M ，van Gils CH ，Keinan-Boker L ，Grace PB ，Bingham SA ，Peeters PH ... -  《-》

Dietary phytoestrogen intake and premenopausal breast cancer risk in a German case-control study.

A diet high in isoflavonoids (soy) is associated with lower breast cancer risk in Asian populations. Due to the low soy intake, dietary lignans may be the more important phytoestrogen class in Western populations. We used a population-based case-control study of breast cancer by age 50 in southern Germany to evaluate the association between dietary intake of different phytoestrogens and premenopausal breast cancer risk. Dietary information was collected from 278 premenopausal cases and 666 age-matched controls, using a validated FFQ. Using multivariate logistic regression, the highest vs. lowest intake quartiles of daidzein and genistein yielded significantly reduced ORs (95% CI) for breast cancer risk of 0.62 (0.40-0.95) and 0.47 (0.29-0.74), respectively. The protective effects of daidzein and genistein were found only for hormone receptor-positive tumors. High intake of other isoflavonoids, e.g., formononetin and biochanin A, as well as the sum of isoflavonoids were not associated with a decrease in risk. Breast cancer risk significantly decreased with a high intake of the plant lignan matairesinol (OR = 0.58, 95% CI 0.37-0.94) but not secoisolariciresinol or the sum of plant lignans. However, both estimated mammalian lignans, enterodiol and enterolactone, were inversely associated with breast cancer risk, with ORs (95% CI) of 0.61 (0.39-0.98) and 0.57 (0.35-0.92), respectively. No effect was found for total phytoestrogen intake. Our results suggest an important role of dietary intake of daidzein and genistein, despite low levels, as well as of matairesinol and mammalian lignans to reduce premenopausal breast cancer risk in this study population.

Linseisen J ，Piller R ，Hermann S ，Chang-Claude J ，German Case-Control Study ... -  《-》

Levels of urinary isoflavones and lignan polyphenols in Japanese women.

Liu W ，Tanabe M ，Harada KH ，Koizumi A ... -  《-》

Phytoestrogen concentrations in serum and spot urine as biomarkers for dietary phytoestrogen intake and their relation to breast cancer risk in European prospective investigation of cancer and nutrition-norfolk.

Grace PB ，Taylor JI ，Low YL ，Luben RN ，Mulligan AA ，Botting NP ，Dowsett M ，Welch AA ，Khaw KT ，Wareham NJ ，Day NE ，Bingham SA ... -  《CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION》