Breast cancer health centre

Breast cancer: Biological therapy - trastuzumab and others

Biological therapy, also called targeted therapy, is a treatment option for certain types of breast cancer known as HER2 positive.

Biological therapies such as trastuzumab, (Herceptin) and lapatinib (Tyverb), work by blocking the effects of growth factors such as HER2 protein that are involved in tumour growth.

Biological therapy is believed to act in three ways to stop cancer cells from growing quickly and out of control:

• It sticks to special receptors on the cancer cells, stopping them from growing.
• It signals the body's own natural killer cells to attack the cancer cells.
• It can work with chemotherapy medications, stopping cancer cells damaged by chemo from repairing themselves.

Other types of antibodies that are being researched to fight cancer include:

• Angiogenesis inhibitors. These antibodies prevent the growth of new blood vessels, cutting off the supply of oxygen and nutrients to cancer cells.
• Signal transduction inhibitors. These antibodies block signals inside the cancer cell that helps the cells divide, stopping the cancer from growing.

Side effects of biological therapy

Side effects can include allergic reactions, difficulty breathing, swelling, nausea, fever or chills, and dizziness or weakness. Talk to your doctor about the possible side effects to watch for.