Trastuzumab as adjuvant treatment for early stage HER2-positive breast cancer — a 10 year history

Abstract

Overexpression of the receptor for human epidermal growth factor type 2 (HER2), or gene amplification for this receptor is observed in approx. 20–25% of breast cancer patients and is associated with a more aggressive course, a higher risk of recurrence and shorter survival. Trastuzumab, a monoclonal antibody, directed to the extracellular domain of the HER2 receptor, was introduced for the treatment of HER2-positive breast cancer in 1998, and its use has caused equal opportunities for patients with HER2-positive breast cancer and those with HER2-negative. In adjuvant treatment of early breast cancer the risk of recurrence is decreased and overall survival is prolonged. The results of international randomised studies, published more than 10 years ago, despite some controversies concerning optimal regimen and duration of treatment, almost immediately became the basis for a change in the standard of care. Currently we know that the optimal administration of trastuzumab is concurrent with taxane-based chemotherapy, but it should not be added to anthracyclines. Long-term observation of the patient population treated in these trials has shown that the introduction of trastuzumab to clinical practice has changed the natural history of HER2-positive early breast cancer. The benefit from this treatment lasts for many years.