Cyclophosphamide, Methotrexate, and Prednisolone With or Without Aromatase Inhibitor Therapy in Treating Postmenopausal Women With Metastatic Breast Cancer

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. PURPOSE: This randomized phase II trial is studying giving cyclophosphamide, methotrexate, and prednisolone together with aromatase inhibitor therapy to see how well it works compared with cyclophosphamide, methotrexate, and prednisolone in treating postmenopausal women with metastatic breast cancer.