All agents have been used in drug regimens for the treatment of breast carcinoma. Which one has specific activity in a subset of female breast cancers?

Trastuzumab Each of the drugs listed has been used in drug regimens for breast cancer, but only trastuzumab has specificity in its actions. The drug is a monoclonal antibody to a surface protein in breast cancer cells that over express the HER2 protein. Consequently, trastuzumab has value in a specific subset of breast cancers.