RATIONALE: Drugs used in chemotherapy, such as cyclophosphamide, methotrexate, and prednisolone, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Estrogen can cause the growth of breast cancer cells. Hormone therapy using anastrozole, letrozole, or exemestane may fight breast cancer by lowering the amount of estrogen the body makes. It is not yet known whether giving combination chemotherapy together with aromatase inhibitor therapy is more effective than combination chemotherapy alone in treating breast cancer.