Megestrol acetate and aminoglutethimide/hydrocortisone in sequence or in combination as second-line endocrine therapy of estrogen receptor-positive metastatic breast cancer: a Southwest Oncology Group phase III trial.
ABSTRACT A phase III randomized trial was performed to determine whether combination hormonal therapy with aminoglutethimide (AG) and hydrocortisone (HC) plus megestrol acetate (MA) improved response rates, response duration, or increased survival over the sequential use of each hormone in women with estrogen receptor-positive metastatic breast cancer (MBC) who had maintained stable disease for at least 6 months or responded to tamoxifen.
Two hundred eighty-eight postmenopausal women with progressive estrogen receptor-positive MBC were randomly selected to receive MA 40 mg four times daily (arm I), AG 250 mg four times daily with HC 40 mg daily in divided doses (arm II), versus the combination of MA plus AG given at the same dosages (arm III). Patients on arms I and II who progressed after an adequate trial were crossed over to the other treatment arm.
Two hundred thirty-five eligible patients were evaluated for response, time to treatment failure, and survival. Response was only reported for patients with measurable disease and was not statistically different among the three arms. There were two partial responses (PRs) on MA (6%), four complete responses (CRs) and six PRs on AG (24%), and eight PRs and three CRs on MA plus AG (23%) in 32, 42, and 48 measurable patients, respectively. Median times to treatment failure were also similar at 5, 4, and 7 months. Survival was also not statistically different among the three arms at 26, 27, and 26 months for arms I, II, and III, respectively. Toxicity was greater in the two AG arms with respect to fatigue, nausea and vomiting, and rash.
With the exception of toxicity, there is no response, time to treatment failure, or survival benefit for any one group when comparing MA, AG, or the combination at their stated doses in women with estrogen receptor-positive MBC who had previously responded to or stabilized with tamoxifen.
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ABSTRACT: The aromatase inhibitor anastrozole inhibits estrogen synthesis. Fulvestrant binds and accelerates degradation of estrogen receptors. We hypothesized that these two agents in combination might be more effective than anastrozole alone in patients with hormone-receptor (HR)-positive metastatic breast cancer. Postmenopausal women with previously untreated metastatic disease were randomly assigned, in a 1:1 ratio, to receive either 1 mg of anastrozole orally every day (group 1), with crossover to fulvestrant alone strongly encouraged if the disease progressed, or anastrozole and fulvestrant in combination (group 2). Patients were stratified according to prior or no prior receipt of adjuvant tamoxifen therapy. Fulvestrant was administered intramuscularly at a dose of 500 mg on day 1 and 250 mg on days 14 and 28 and monthly thereafter. The primary end point was progression-free survival, with overall survival designated as a prespecified secondary outcome. The median progression-free survival was 13.5 months in group 1 and 15.0 months in group 2 (hazard ratio for progression or death with combination therapy, 0.80; 95% confidence interval [CI], 0.68 to 0.94; P=0.007 by the log-rank test). The combination therapy was generally more effective than anastrozole alone in all subgroups, with no significant interactions. Overall survival was also longer with combination therapy (median, 41.3 months in group 1 and 47.7 months in group 2; hazard ratio for death, 0.81; 95% CI, 0.65 to 1.00; P=0.05 by the log-rank test), despite the fact that 41% of the patients in group 1 crossed over to fulvestrant after progression. Three deaths that were possibly associated with treatment occurred in group 2. The rates of grade 3 to 5 toxic effects did not differ significantly between the two groups. The combination of anastrozole and fulvestrant was superior to anastrozole alone or sequential anastrozole and fulvestrant for the treatment of HR-positive metastatic breast cancer, despite the use of a dose of fulvestrant that was below the current standard. (Funded by the National Cancer Institute and AstraZeneca; SWOG ClinicalTrials.gov number, NCT00075764.).New England Journal of Medicine 08/2012; 367(5):435-44. · 53.30 Impact Factor
Article: Endocrine therapy of breast cancer.Annals of Oncology 02/2002; 13 Suppl 4:61-8. · 6.43 Impact Factor