title: Letrozole as adjuvant endocrine therapy in postmenopausal women with breast cancer.
abstract: The third-generation aromatase inhibitor letrozole offers a promising approach to treating hormone-sensitive breast cancer for postmenopausal women, through potent and specific inhibition of estrogen synthesis. In neoadjuvant and first-line treatment, letrozole demonstrated superior efficacy compared with tamoxifen in randomized Phase III trials. Initial results of Breast InterGroup 1-98, a large ongoing randomized trial investigating primary adjuvant endocrine treatment with either letrozole or tamoxifen, have recently been presented. Patients treated with letrozole demonstrated a 19% improvement in disease-free survival and a significant reduced risk of distant recurrences, holding out the prospect of a survival advantage over tamoxifen treatment with further maturation of the trial. For patients who have already completed 5 years of tamoxifen, extended endocrine therapy with letrozole is a new therapeutic option based on the results of the MA-17 trial. The optimal use of aromatase inhibitors remains an open question, at least until results from randomized trials (BIG 1-98, TEAM) investigating the sequential use of an aromatase inhibitor and tamoxifen in comparison with continuous monotherapy become available.
authors.affiliation: Department of Oncology/Hematology, Kantonsspital St Gallen, CH -9007 St Gallen, Switzerland. dieter.koeberle@kssg.ch
authors.forename: Dieter
authors.initials: D
authors.lastname: Koeberle
authors.forename: Beat
authors.initials: B
authors.lastname: Thuerlimann
mesh_terms: D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D000077289:Letrozole; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009570:Nitriles / Q000627:therapeutic use*; D017698:Postmenopause; D016032:Randomized Controlled Trials as Topic; D013629:Tamoxifen / Q000627:therapeutic use; D014230:Triazoles / Q000627:therapeutic use*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D013629:Tamoxifen; D000077289:Letrozole