Targeted therapy for HER-2: Personalized medicine for her, too

摘要

In the past decade, it has been realized that rather than a single entity, breast cancer represents a spectrum of neoplastic disorders affecting the same organ (1-4). The expression of human epidermal growth factor receptor-2 (HER-2) is characteristic of subtype(s) of breast cancer with an unfavorable prognosis. In 1997 the approval by the United States Food and Drug Agency (FDA) of rituximab, monoclonal antibody against CD20 antigen expressed on the surface of lymphoma cells, has ushered in a new era of molecularly targeted therapy in the medical treatment of cancer. The approval of trastuzumab, the monoclonal antibody against HER-2, followed in 1998. The introduction of trastuzumab has been a true milestone and meant a significant progress in the management of HER-2 positive breast cancers. Trastuzumab was first proven to be effective in patients with metastatic disease (5). Metastatic breast cancer is, in most cases, an incurable disease, and in order to affect population mortality, a drug has to demonstrate activity in patients presenting at an earlier stage. In subsequent prospective clinical trials, the addition of trastuzumab to the adjuvant therapy reduced the recurrence rate and resulted in significant prolongation of survival (6-8).