title: Efficacy of tamoxifen following anastrozole ('Arimidex') compared with anastrozole following tamoxifen as first-line treatment for advanced breast cancer in postmenopausal women.
abstract: Anastrozole ('Arimidex') is indicated for the treatment of advanced breast cancer in postmenopausal women. Combined analysis of two international randomised, double-blind trials (n=1021) showed that in patients with hormone receptor-positive tumours, first-line treatment with anastrozole significantly prolonged the time to progression (TTP) compared with tamoxifen (median TTP: 10.7 versus 6.4 months, respectively; P=0.022). Second-line tamoxifen following anastrozole, or vice versa, in this trial population was unblinded. The treatments were crossed over and then efficacy was assessed using a questionnaire. Of 511 patients randomised to anastrozole, 137 (26.8%) received second-line tamoxifen. Questionnaire data were available for 119 patients; 58 (48.7%) gained clinical benefit (CB=complete+partial response (CR+PR)+(stable disease (SD) >/=24 weeks)), while 12 (10.1%) had an objective response (OR=CR+PR). Of 510 patients randomised to tamoxifen, 134 (26.3%) received second-line anastrozole. Questionnaire data from 95 patients showed that 54 (56.8%) gained CB and 7 of the patients gaining CB (7.4%) had an OR. Previous studies showed anastrozole is effective after first-line tamoxifen. These data show that the sequential administration of first-line anastrozole followed by tamoxifen provides effective use of these drugs in the treatment of postmenopausal women with advanced breast cancer.
authors.affiliation: Senology Center of Eastern Switzerland, for the Swiss Group for Clinical Cancer Research SAKK (President: A Goldhirsch), Senology Center of Eastern Switzerland, Kantonsspital, 9007, St Gallen, Switzerland. beat.thuerlimann@kssg.ch
authors.forename: B
authors.initials: B
authors.lastname: Thürlimann
authors.forename: J F R
authors.initials: JF
authors.lastname: Robertson
authors.forename: J M
authors.initials: JM
authors.lastname: Nabholtz
authors.forename: A
authors.initials: A
authors.lastname: Buzdar
authors.forename: J
authors.initials: J
authors.lastname: Bonneterre
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077384:Anastrozole; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009570:Nitriles / Q000008:administration & dosage; D017698:Postmenopause; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D013629:Tamoxifen / Q000008:administration & dosage; D016896:Treatment Outcome; D014230:Triazoles / Q000008:administration & dosage
chemical_list: D009570:Nitriles; D014230:Triazoles; D013629:Tamoxifen; D000077384:Anastrozole