Targeted therapy for HER2 positive breast cancer

INTRODUCTION: Breast cancer is the second most common cause of death for women behind lung cancer and the most common cause of cancer deaths for women aged 45–55 years old (CDC.gov 2012). Although there continue to be enormously large numbers of disease incidence, deaths have been declining due to the disease with two hallmark time frames. The first occurred during the mid to late 1980’s when hormonal therapy was introduced as a treatment for ER/PR positive breast cancer. The second occurred in the late 1990’s when trastuzumab was introduced in treating HER2 positive breast cancer. These remarkable accomplishments in developing novel targeted therapies for breast cancer, along with a better understanding of the disease biology have improved disease outcome over the past 20 years. This article reviews the data presented at 2012 American Society of Clinical Oncology and 2012 San Antonio Breast Cancer Symposium regarding progress made in the field of HER2 positive breast cancer and examines the future of HER2 targeted therapy.