Several recent advances have led to accelerated progress in breast cancer therapy. The development of new drugs with novel mechanisms of action, such as the taxanes, or oral bioavailability, such as capecitabine, has expanded the horizons of available chemotherapy. The use of tumor-related proteins or genes as markers of sensitivity or resistance to systemic therapy may allow for more predictable outcomes. Finally, the emergence of biological therapies such as the HER2/neu monoclonal antibody trastuzumab (Herceptin; Genentech, Inc, So. San Francisco, CA) represents an exciting new direction that opens doors to new concepts in antitumor therapy. This report will review the most exciting possibilities for expanding the field of breast cancer management.