title: Expression of estrogen receptor alpha and beta in breast cancers of pre- and post-menopausal women.
abstract: Expression of estrogen receptors (ER) is clinically relevant in designing therapeutic strategies. The relative importance of the two types of estrogen receptors (ER-alpha and ER-beta) in human breast cancers in pre- and post-menopausal women has not been properly defined. To determine the possible association between the expression of estrogen receptor and serum estradiol levels in pre- and post-menopausal women with breast cancer. 44 patients with invasive ductal carcinoma of the breast were studied and a breast tissue biopsy was taken. ER-alpha and ER-beta were detected by immunocytochemistry. Serum levels of estradiol and estrone were measured by radioimmunoassay and FSH was measured using IRMA. We studied 21 pre- and 23 post-menopausal women with breast carcinoma. Examining the number of cases with tumors positive for ER, we found no differences in the frequency of ER-alpha between pre- and post-menopausal women, but ER-beta decreased marginally after menopause (p < 0.051). In cases with tumors positive for ER, the proportion of cells positive for ER-alpha was similar post-menopausally (53.95%) and pre-menopausally (57.21%), but for ER-beta the number of positive cells decreased significantly after menopause (p < 0.051). In pre-menopausal women there was a correlation between serum estradiol levels and ER-beta; in post-menopausal women there was a correlation between serum FSH levels and ER-alpha. These results indicate that estradiol levels in women with mammary carcinoma are related to ER-beta expression in the breast tumor tissue.
authors.affiliation: Instituto Mexicano del Seguro Social, Unidad de Investigación en Epidemiología Clínica, León, Guanajuato, Mexico. bomo907@hotmail.com
authors.forename: Blanca
authors.initials: B
authors.lastname: Murillo-Ortiz
authors.forename: Elva
authors.initials: E
authors.lastname: Pérez-Luque
authors.forename: J M
authors.initials: JM
authors.lastname: Malacara
authors.forename: Leonel
authors.initials: L
authors.lastname: Daza-Benítez
authors.forename: Martha
authors.initials: M
authors.lastname: Hernández-González
authors.forename: Luis
authors.initials: L
authors.lastname: Benítez-Bribiesca