Adjuvant targeted therapy in early breast cancer.

ABSTRACT

For this review, the authors appraised the evidence for adjuvant trastuzumab therapy in early breast cancer. There was level 1 evidence to support the routine use of 1 year of adjuvant trastuzumab in conjunction with chemotherapy for women with human epidermal growth factor receptor 2 (HER-2)-positive early breast cancer. The relative benefits of concurrent versus sequential administration remained unclear; however concurrent administration permitted the earliest possible intervention with trastuzumab with possible superiority. There was evidence to support the use of trastuzumab in both lymph node-positive and high-risk lymph node-negative patients, and preliminary data suggested that all patient subgroups that were eligible for the trials benefit equally from trastuzumab. Adjuvant trastuzumab was associated with a risk of cardiotoxicity, the long-term impact of which remains largely unknown. Routine cardiac risk assessment considering left ventricular ejection fraction, age, and prior history of cardiac events is recommended along with the selection of trastuzumab-based regimens that minimize cardiotoxicity. Trastuzumab acquisition costs for 1 year of therapy were the largest component of treatment costs.