Cardiotoxic effects of trastuzumab.

Breast cancer with overexpression of the HER2 receptor is an aggressive type of breast cancer with poor prognosis. Trastuzumab (Herceptin) is a monoclonal antibody that binds to the HER2 receptor on the cell surface blocking the signals that promote cell-growth proliferation. Trastuzumab treatment has almost halved the risk of relapse, when given as an adjuvant, and has improved the overall survival in metastatic breast cancer. However, when given alone or in combination with cardiotoxic chemotherapy, especially anthracyclines, trastuzumab may lead to congestive heart failure of varying severity.