Targeted therapy in her2-positive metastatic breast cancer: a review of the literature.

Breast tumours positive for her2 (human epidermal growth factor receptor 2) represent approximately 20% of all breast cancer cases and are associated with an aggressive natural history. The advent of targeted anti-her2 therapies has dramatically improved disease control and survival in patients with metastatic her2-positive breast cancer. Targeted agents are now considered the standard of care in the first-line setting and beyond. The present review summarizes the currently available data on targeted anti-her2 therapies from completed randomized phase iii clinical trials and briefly discusses emerging advances that will address unmet needs in metastatic her2-positive breast cancer.