Targeted Therapy in HER2-Positive Breast Cancer.

ABSTRACT

Categorization, risk assessment, and treatment of breast cancer have been revolutionized by the original description of the human epidermal growth factor receptor 2 (HER2), first as a prognostic marker and then as a therapeutic target. The HER2-positive subtype of breast cancer represents less than approximately 20% of the incident breast cancers. Nevertheless, many lessons can be learned from the development of anti-HER2 therapies in early-stage disease. This review will comment on the key studies in both the (neo)adjuvant and metastatic settings and discusses some of the controversies that still remain today both in clinical care and as research questions.