Randomized trial of tamoxifen versus tamoxifen plus aminoglutethimide as adjuvant treatment in postmenopausal breast cancer patients with hormone receptor-positive disease: Austrian Breast and Colorectal Cancer Study Group trial 6

Purpose : To determine whether the addition of aminoglutethimide to tamoxifen is able to improve the outcome in postmenopausal patients with hormone receptor-positive, early-stage breast cancer. Patients and Methods: A total of 2,021 postmenopausal women were randomly assigned to receive either tamoxifen for 5 years alone or tamoxifen in combination with aminoglutethimide (500 mg/d) for the first 2 years of treatment. Tamoxifen was administered at 40 mg/d for the first 2 years and at 20 mg/d for 3 years. Results: All randomized and eligible patients were included in the analysis according to the intention-to-treat principle. After a median follow-up of 5.3 years, the 5-year disease-free survival in the aminoglutethimide plus tamoxifen group was 83.6% versus 83.7% in the monotherapy group (P =.89). The corresponding data for overall survival at 5 years were 91.4% and 91.2%, respectively (P =.74). More patients failed to complete combination treatment (13.7%) because of side effects as compared to tamoxifen alone (5.2%; P =.0001). Conclusion: Aminoglutethimide given for 2 years in addition to tamoxifen for 5 years does not improve the prognosis of postmenopausal patients with receptor-positive, lymph node-negative or lymph node-positive breast cancer. J Clin Oncol 21:984-990. (C) 2003 by American Society of Clinical Oncology.