Standard Chemotherapy Compared With High-Dose Combination Chemotherapy and Peripheral Stem Cell Transplantation in Treating Women With Breast Cancer

RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Peripheral stem cell transplantation may allow doctors to give higher doses of chemotherapy drugs and kill more tumor cells. It is not yet known which treatment regimen is more effective for breast cancer. PURPOSE: Randomized phase III trial to compare the effectiveness of standard cyclophosphamide, methotrexate, and fluorouracil with that of high-dose combination chemotherapy plus peripheral stem cell transplantation in treating women who have stage II or stage IIIA breast cancer.