 New treatment strategies are needed to improve the clinical outcome in breast cancer patients at high risk of tumor recurrence. Even with the best present combination chemotherapy, radiotherapy and surgery, the five-year rate of disease recurrence and death is at least 60 in patients with locally advanced breast cancer. Recent advances that may improve clinical outcome include the use of taxanes paclitaxel and docetaxel, a new class of cytotoxic agents, with reported higher response rates than standard anthracycline-based chemotherapy. Understanding the in vivo mechanism of action of chemotherapeutic agents would also allow for rational combination of agents. For example, if apoptosis is the main mechanism of therapeutic action, then future developments in restoring function of p53 by gene therapy or treatment with apoptosis regulating molecules may prove to be important future advances in the treatment of cancer. If specific therapeutic targets and pathways are identified, new molecules with selective action against these targets may be developed, which may have potential for decreased toxicity with increased efficacy. 