Anastrozole versus megestrol acetate in the treatment of postmenopausal women with advanced breast carcinoma: results of a survival update based on a combined analysis of data from two mature phase III trials. Arimidex Study Group.
Jones, Stephen E
Blomqvist, Carl P
Vogel, Charles L
Wolter, Janet M
AffiliationDepartment of Breast Medical Oncology, the University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
MetadataShow full item record
AbstractBACKGROUND: This report presents the results of a survival update based on the combined data from two studies that compared the efficacy and tolerability of anastrozole (1 or 10 mg once daily), a selective, nonsteroidal aromatase inhibitor administered orally, and megestrol acetate (40 mg 4 times daily) in the treatment of postmenopausal women with advanced breast carcinoma whose disease had progressed after treatment with tamoxifen. METHODS: Two randomized, parallel-group, multicenter trials were conducted, involving a total of 764 patients. The two trials were identical in design; both were double blind for anastrozole and open label for megestrol acetate. Overview analyses were conducted with the intent of strengthening the interpretation of results from each trial. The median follow-up duration for this survival update was 31 months. RESULTS: At the clinical dose of 1 mg daily, anastrozole demonstrated a statistically significant survival advantage over megestrol acetate, with a hazard ratio of 0.78 (P < 0.025)(0.60 < 97.5% confidence interval [CI] <1.0). The 1 mg anastrozole group also had a longer median time to death (26.7 months) compared with 22.5 months for the megestrol acetate group. The 10 mg anastrozole group also had a survival benefit over the megestrol acetate group, with a hazard ratio of 0.83 (P=0.09, not significant)(0.64 < 97.5% CI < 1.1). Higher 2-year survival rates were observed for both anastrozole treatment groups than for the megestrol acetate group (56.1%, 54.6%, and 46.3% for the groups given 1 mg anastrozole, 10 mg anastrozole, and megestrol acetate, respectively). CONCLUSIONS: This combined analysis of two trials of postmenopausal patients with advanced breast carcinoma has clearly demonstrated that, after disease progression with tamoxifen, treatment with anastrozole 1 mg once daily results in a statistically and clinically significant advantage over a standard treatment, megestrol acetate. This important benefit, in addition to the good tolerability profile of anastrozole, supports the use of this drug as a valuable new treatment option for this patient population.
CitationAnastrozole versus megestrol acetate in the treatment of postmenopausal women with advanced breast carcinoma: results of a survival update based on a combined analysis of data from two mature phase III trials. Arimidex Study Group. 1998, 83 (6):1142-52 Cancer
- A phase III trial comparing anastrozole (1 and 10 milligrams), a potent and selective aromatase inhibitor, with megestrol acetate in postmenopausal women with advanced breast carcinoma. Arimidex Study Group.
- Authors: Buzdar AU, Jones SE, Vogel CL, Wolter J, Plourde P, Webster A
- Issue date: 1997 Feb 15
- Anastrozole, a potent and selective aromatase inhibitor, versus megestrol acetate in postmenopausal women with advanced breast cancer: results of overview analysis of two phase III trials. Arimidex Study Group.
- Authors: Buzdar A, Jonat W, Howell A, Jones SE, Blomqvist C, Vogel CL, Eiermann W, Wolter JM, Azab M, Webster A, Plourde PV
- Issue date: 1996 Jul
- Anastrozole alone or in combination with tamoxifen versus tamoxifen alone for adjuvant treatment of postmenopausal women with early-stage breast cancer: results of the ATAC (Arimidex, Tamoxifen Alone or in Combination) trial efficacy and safety update analyses.
- Authors: Baum M, Buzdar A, Cuzick J, Forbes J, Houghton J, Howell A, Sahmoud T, ATAC (Arimidex, Tamoxifen Alone or in Combination) Trialists' Group.
- Issue date: 2003 Nov 1
- Extended adjuvant therapy with anastrozole among postmenopausal breast cancer patients: results from the randomized Austrian Breast and Colorectal Cancer Study Group Trial 6a.
- Authors: Jakesz R, Greil R, Gnant M, Schmid M, Kwasny W, Kubista E, Mlineritsch B, Tausch C, Stierer M, Hofbauer F, Renner K, Dadak C, Rücklinger E, Samonigg H, Austrian Breast and Colorectal Cancer Study Group.
- Issue date: 2007 Dec 19
- Anastrozole ('Arimidex') versus tamoxifen as first-line therapy in postmenopausal women with advanced breast cancer: results of the double-blind cross-over SAKK trial 21/95--a sub-study of the TARGET (Tamoxifen or 'Arimidex' Randomized Group Efficacy and Tolerability) trial.
- Authors: Thürlimann B, Hess D, Köberle D, Senn I, Ballabeni P, Pagani O, Perey L, Aebi S, Rochlitz C, Goldhirsch A
- Issue date: 2004 Jun