Optimising the role of herceptin in breast cancer

The humanised monoclonal antibody Herceptin® targets human epidermal growth factor receptor-2 (HER2) positive cells, i.e. cells in which HER2 is overexpressed, a feature associated with many tumour characteristics. Approximately 20-30% of breast cancers are HER2 positive and are known to be particularly aggressive. Thus, HER2-positive clinical trials of Herceptin® have clearly demonstrated that it provides significant clinical benefit in HER2-positive metastatic dis-ease, most importantly increased survival when administered first line in combination with chemotherapy. The articles in this supplement review our knowledge of the activity of HER2 and how to test for HER2 status, and describe the clinical trials of Herceptin® that have been performed today. In conclusion, future research with this novel agent is likely to change the management of cancer patients and further improve the efficacy of therapy.