Trastuzumab (Herceptin) is a monoclonal antibody against the extracellular domain of HER-2 CARTER1992 and was approved for treatment of patients with HER-2 positive metastatic breast cancer in the 1990´s VOGEL 2002. Later, trastuzumab was approved for the use following anthracycline-based chemotherapies to decrease disease progression and to improve survival. The combination of anthracyclines and trastuzumab in the adjuvant setting reduced the risk of breast cancer relapse by 50% and the risk of death from breast cancer by 33% PICCARD 2005 und ROMOND 2005.