Novel treatment options in the management of metastatic breast cancer.

Few breast cancer patients present with metastatic disease at the initial diagnosis. However, approximately one-quarter of patients with lymph node-negative disease and one half of patients with lymph node-positive tumors will ultimately develop distant recurrent breast cancer. Standard treatment of metastatic breast cancer generally includes systemic treatment and surgery or radiation as needed and when indicated for palliation of localized symptomatic metastases. Extending survival and improving quality of life are the primary focus of patient management; thus, there is a preference for the use of minimally toxic treatments. Taxanes have played a significant role in improving outcomes, but many patients still experience disease progression. Many new and emerging agents have been developed for metastatic breast cancer, including both biologic therapies and chemotherapies. A common theme among these therapies is their ability to target specific molecules or processes unique to cancer cells, enhancing the potency and reducing many of the toxicities typically observed with standard cytotoxic chemotherapies. Such agents include poly(ADP)-ribose polymerase inhibitors (iniparib), trastuzumab-DM1, everolimus, the epothilones (ixabepilone), and eribulin. Although metastatic breast cancer remains incurable, the introduction of new agents and new treatment approaches has led to an incremental build-up in terms of survival benefits.