Anastrozole is superior to tamoxifen as first-line therapy in hormone receptor positive advanced breast carcinoma - Results of two randomized trials designed for combined analysis

Citation
J. Bonneterre et al., Anastrozole is superior to tamoxifen as first-line therapy in hormone receptor positive advanced breast carcinoma - Results of two randomized trials designed for combined analysis, CANCER, 92(9), 2001, pp. 2247-2258
Citations number
19
Categorie Soggetti
Oncology,"Onconogenesis & Cancer Research
Journal title
CANCER
ISSN journal
0008543X → ACNP
Volume
92
Issue
9
Year of publication
2001
Pages
2247 - 2258
Database
ISI
SICI code
0008-543X(20011101)92:9<2247:AISTTA>2.0.ZU;2-O
Abstract
BACKGROUND. Two randomized, double-blind trials have compared tamoxifen 20 mg daily and the selective, nonsteroidal aromatase inhibitor anastrozole I mg daily as first-line therapy for advanced breast carcinoma (ABC) in postm enopausal women. The trials were prospectively designed to allow for combin ed data analyses. METHODS. The combined study population included 1021 postmenopausal women ( median age, 67 years [range, 30-92]) with ABC whose tumors were either estr ogen and/or progesterone receptor positive or of unknown receptor status. P rimary endpoints were time to progression (TTP), objective response, and to lerability. RESULTS. At a median duration of follow-up of 18.2 months, anastrozole was at least equivalent to tamoxifen in terms of median TTP (8.5 and 7.0 months , respectively; estimated hazard ratio [tamoxifen relative to anastrozole], 1.13 [lower 95% confidence level, 1.00]). In a retrospective subgroup anal ysis, anastrozole was superior to tamoxifen with respect to TTP (median val ues of 10.7 and 6.4 months for anastrozole and tamoxifen, respectively, two -sided P = 0.022) in patients with estrogen and/or progesterone receptor po sitive tumors (60% of combined trial population). In terms of objective res ponse, 29.0% of anastrozole and 27.1% of tamoxifen patients achieved either a complete response (CR) or a partial response (PR). Clinical benefit (CR + PR + stabilization of greater than or equal to 24 weeks) rates were 57.1% and 52.0% for anastrozole and tamoxifen, respectively. Both anastrozole an d tamoxifen were well tolerated. Anastrozole led to significantly fewer ven ous thromboembolic (P = 0.043; not adjusted for multiple comparisons) event s, and vaginal bleeding was reported in fewer patients treated with anastro zole than with tamoxifen. CONCLUSIONS. in postmenopausal women with hormonally sensitive ABC, anastro zole should be considered as the new standard first-line treatment. (C) 200 1 American Cancer Society.