OUTLINE: All patients receive sequential chemotherapy regimens consisting of 3 courses each of doxorubicin, paclitaxel, and cyclophosphamide on a schedule of one course every 14 days. Following completion of chemotherapy, patients who underwent breast conservation surgery receive radiotherapy. Mastectomy patients with 10 or more positive nodes or with T3-4 tumors are also eligible for delayed radiotherapy. Patients who are hormone receptor positive (or whose receptor status is unknown) are treated with oral tamoxifen for 5 years, beginning after completion of all other therapy. Patients are followed every 3 months for 2 years, every 6 months for 3 years, then yearly.