RATIONALE: Drugs used in chemotherapy, such as doxorubicin hydrochloride, cyclophosphamide, docetaxel, and zoledronic acid, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) may kill more tumor cells. It is not yet known whether combination chemotherapy is more effective when given together with zoledronic acid in treating patients with breast cancer.