Breast Cancer Treatment: Targeted therapy

Monoclonal antibody treatment uses antibodies made in the laboratory from a type of immune system cell. These antibodies identify substances that may help cancer cells grow. The antibodies work by attaching to the substance to kill the cancer cells, block their growth or keep them from spreading. Monoclonal antibodies are given through a vein with an IV. They may be used alone or to carry drugs or radioactive material directly to the cancer cells.

Trastuzumab (Herceptin) is a monoclonal antibody that blocks the effects of the growth factor protein HER2, which sends growth signals to breast cancer cells. About 25 percent of breast cancer patients have tumors that may be treated with trastuzumab combined with chemotherapy.

Tyrosine kinase inhibitors are targeted drugs that block the signals needed for tumors to grow. Tyrosine kinase inhibitors are sometimes used in combination with other anticancer drugs as adjuvant therapy.

Lapatinib is a tyrosine kinase inhibitor that blocks the effects of the HER2 protein and other proteins inside tumor cells. It may be used to treat patients with HER2-positive breast cancer that has progressed following treatment with Herceptin (trastuzumab).