Phytoestrogens and breast cancer prevention: possible mechanisms of action.
OBJECTIVE
Phytoestrogens display an array of pharmacologic properties, and in recent years investigation of their potential as anticancer agents has increased dramatically. In this article we review the published literature related to phytoestrogens and breast cancer as well as suggest the possible mechanisms that may underlie the relationship between phytoestrogens and breast cancer.


METHODS
Electronic searches on phytoestrogens and breast cancer were performed on MEDLINE and EMBASE in June 2007. No date restriction was placed on the electronic search.


METHODS
We focused on experimental data from published studies that examined the characteristics of phytoestrogens using in vivo or in vitro models. We also include human intervention studies in this review.


RESULTS
We evaluated evidence regarding the possible mechanisms of phytoestrogen action. Discussions of these mechanisms were organized into those activities related to the estrogen receptor, cell growth and proliferation, tumor development, signaling pathways, and estrogen-metabolizing enzymes.


CONCLUSIONS
We suggest that despite numerous investigations, the mechanisms of phytoestrogen action in breast cancer have yet to be elucidated. It remains uncertain whether these plant compounds are chemoprotective or whether they may produce adverse outcomes related to breast carcinogenesis.
Mense
Sarah M
SM
Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032, USA.
Hei
Tom K
TK
Ganju
Ramesh K
RK
Bhat
Hari K
HK
D000818:Animals; D016588:Anticarcinogenic Agents / Q000009:adverse effects / Q000145:classification / Q000494:pharmacology*; D001141:Aromatase / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D049108:Cell Enlargement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004032:Diet; D004967:Estrogens / Q000096:biosynthesis; D006801:Humans; D048789:Phytoestrogens / Q000009:adverse effects / Q000145:classification / Q000494:pharmacology*; D011960:Receptors, Estrogen / Q000378:metabolism; D012307:Risk Factors; D015398:Signal Transduction
D016588:Anticarcinogenic Agents; D004967:Estrogens; D048789:Phytoestrogens; D011960:Receptors, Estrogen; D003577:Cytochrome P-450 Enzyme System; D001141:Aromatase