Estrogens, phytoestrogens and colorectal neoproliferative lesions.
Epidemiological and experimental studies suggest a protective role of estrogens against colorectal cancer. This effect seems to be mediated by their binding to estrogen receptor beta (ER-beta), one of the two estrogen receptors with high affinity for these hormones. Very recently, the demonstration of an involvement of ER-beta in the development of adenomatous polyps of the colon has also been documented, suggesting the use of selective ER-beta agonists in primary colorectal cancer prevention. Phytoestrogens are plant-derived compounds that structurally and functionally act as estrogen-agonists in mammals. They are characterized by a higher binding affinity to ER-beta as compared to estrogen receptor alpha (ER-alpha), the other estrogen receptor subtype. These biological characteristics explain why the administration of phytoestrogens does not produce the classical side effects associated to estrogen administration (cerebro- and cardio-vascular accidents, higher incidence of endometrial and breast cancer) and makes these substances ideal candidates for the prevention of colorectal cancer.
Barone
Michele
M
Facolta' di Medicina e Chirurgia, Universita' di Bari, Bari, Italy, m.barone@gastro.uniba.it.
Tanzi
Sabina
S
Lofano
Katia
K
Scavo
Maria Principia
MP
Guido
Raffaella
R
Demarinis
Lucia
L
Principi
Maria Beatrice
MB
Bucci
Antongiulio
A
Di Leo
Alfredo
A