OUTLINE: This is a randomized, multicenter study. Patients are stratified according to age (under 50 vs 50 and over), clinical tumor size (less than 2.1 cm vs 2.1-4.0 cm vs greater than 4.0 cm), clinical nodal status (negative vs positive), and participating center. Patients are randomized to one of three treatment arms. Arm I: Patients receive doxorubicin IV followed by cyclophosphamide IV over 30 minutes to 2 hours on day 1 every 21 days for 4 courses. Patients receive oral tamoxifen daily for 5 years, starting on day 1. After completion of chemotherapy, patients are offered surgery (e.g., lumpectomy with axillary node dissection, or modified radical mastectomy). Post-operative radiotherapy is given post-lumpectomy. Arm II: Patients receive doxorubicin IV followed by cyclophosphamide IV over 30 minutes to 2 hours followed by docetaxel IV over 1 hour on day 1 once every 21 days for 4 courses. Patients receive oral tamoxifen daily for 5 years, starting on day 1. After the completion of chemotherapy, surgery is offered (as in arm I). Radiotherapy follows surgery in post-lumpectomy patients. Arm III: Patients receive doxorubicin IV followed by cyclophosphamide IV over 30 minutes to 2 hours on day 1 every 21 days for 4 courses. Patients receive oral tamoxifen daily for 5 years, starting on day 1. After completion of chemotherapy, surgery is offered (as in arm I). After surgical recovery, docetaxel IV is given over 1 hour once every 21 days for 4 courses. Radiotherapy follows docetaxel in post-lumpectomy patients. Chemotherapy is repeated every 21 days for 4 courses in the absence of disease progression or unacceptable toxicity. Patients are followed every 6 months for 5 years, and then annually thereafter.