title: Estrogen receptors: role in breast cancer.
abstract: The estrogen receptor (ER) exists in two forms known as ERalpha and ERbeta. Currently, a clinical role has only been established for ERalpha. The primary use of ERalpha in breast cancer is for predicting likely response to hormone treatment. Patients with breast cancers expressing ERalpha are approximately seven to eight times more likely to benefit from endocrine therapy than ERalpha-negative patients. For the initial three to five years after primary diagnosis, ERalpha-positive patients generally have a better outcome than ERalpha-negative patients. Overall, however, the prognostic value of ERalpha is relatively weak and only of limited value in the clinically important subgroup of patients with lymph node-negative disease. Further work is required to establish if ERbeta has a clinical role in breast cancer.
authors.affiliation: Department of Nuclear Medicine, St Vincent's University Hospital, Elm Park, Dublin 4, Ireland. Michael.J.Duffy@ucd.ie
authors.forename: M J
authors.initials: MJ
authors.lastname: Duffy
mesh_terms: D000077384:Anastrozole; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D007987:Gonadotropin-Releasing Hormone; D020249:Hormone Replacement Therapy / Q000379:methods*; D006801:Humans; D000077289:Letrozole; D008954:Models, Biological; D009570:Nitriles / Q000627:therapeutic use; D020845:Selective Estrogen Receptor Modulators / Q000627:therapeutic use*; D013629:Tamoxifen / Q000627:therapeutic use; D014230:Triazoles / Q000627:therapeutic use
chemical_list: D047072:Aromatase Inhibitors; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D009570:Nitriles; D020845:Selective Estrogen Receptor Modulators; D014230:Triazoles; D013629:Tamoxifen; D000077384:Anastrozole; D007987:Gonadotropin-Releasing Hormone; D000077289:Letrozole