ABSTRACT
Breast cancer is the most frequently diagnosed malignant disease in women and the second-leading cause of cancer death after lung cancer. Patients with breast cancer in which the HER2-neu growth factor receptor is amplified or overexpressed are likely to have poorly differentiated tumours with a high proliferative rate, positive axillary lymph nodes and decreased expression of oestrogen and progesterone receptors. Twenty to 30 per cent of women with early stage breast cancer have the expression of HER2-neu in their tumours. Trastuzumab is a monoclonal antibody directed against the HER2-neu receptor that has been shown to improve outcomes, including survival, for patients with metastatic HER2-positive disease. The role of trastuzumab in adjuvant therapy for early-stage disease has been the subject of four large multicentre randomised controlled trials. The Herceptin adjuvant (HERA) trial found a 46 per cent reduction in breast cancer recurrence and a 34 per cent survival benefit by giving trastuzumab as an adjuvant treatment.
