"The use of trastuzumab (Herceptin®) as the backbone of treatment for patients with overexpression of the HER2 gene and amplification of the HER2 protein product has transformed the approach to the subgroup of patients expressing this phenotype. Indeed from a group of patients with the worst prognosis and greatest resistance to chemotherapy HER2 positive patients receiving Herceptin® and chemotherapy have the highest response rate and survival. It appears that the use of targeted therapy against this relevant biologic receptor has substantially altered the natural history of the disease."