title: Paradoxical clinical effect of estrogen on breast cancer risk: a "new" biology of estrogen-induced apoptosis.
abstract: Administration of estrogen replacement therapy (ERT) decreases the incidence of breast cancer, as shown in a double-blind, placebo-controlled randomized trial of the Women's Health Initiative (WHI) in 10,739 postmenopausal women with a prior hysterectomy. Although paradoxical because estrogen is recognized to stimulate breast cancer growth, laboratory data support a mechanism of estrogen-induced apoptosis under the correct environmental circumstances. Long-term antiestrogen treatment or estrogen deprivation causes the eventual development and evolution of antihormone resistance. Cell populations emerge with a vulnerability, as estrogen is no longer a survival signal but is an apoptotic trigger. The antitumor effect of ERT in estrogen-deprived postmenopausal women is consistent with laboratory models.
authors.affiliation: Georgetown Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA. vcj2@georgetown.edu
authors.forename: V Craig
authors.initials: VC
authors.lastname: Jordan
authors.forename: Leslie G
authors.initials: LG
authors.lastname: Ford
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D012307:Risk Factors
chemical_list: D004967:Estrogens