Medications that specifically target an abnormality within the cancer cells may be able to offer extra benefits and few side effects.
Herceptin (chemical name: trastuzamab) is the best known medicine of this type. Herceptin is an immune targeted therapy and works only against breast cancers that have extra HER2 genes and make too many HER2 protein receptors. These receptors work like parking spots on breast cancer cells. They receive signals telling the cells to grow and spread. Herceptin targets and blocks the parking places, so the signals to grow and spread can't be delivered. Herceptin also hooks on to the cancer cells and "marks" them. The immune system notices these marked cells and destroys them. Herceptin is very effective in people with HER2-positive breast cancer who have early- or late- (advanced) stage disease.
Herceptin has several potential side effects:
- It may cause flu-like symptoms (chills, fever, nausea, vomiting, headache, pain).
- It can sometimes cause heart damage. To minimize this risk, Herceptin is not given with other drugs that can also damage the heart. There is little risk to the heart when you take Herceptin alone.
Avastin (chemical name: bevacizumab) is another targeted therapy. Avastin targets the new blood vessels that feed cancer cells. Avastin has been approved by the United States Food and Drug Administration (FDA) in combination with Taxol (chemical name: paclitaxel) to treat metastatic HER2-negative breast cancer in people who have not already received chemotherapy for metastatic breast cancer.
Avastin has a number of potentially serious side effects including high blood pressure, nose bleeds, and extra protein in the urine. Avastin also may increase the risk of stroke and heart problems. If you already have any of these conditions or are at high risk for them, talk to your doctor about how Avastin may affect them.
New targeted therapies are emerging on a regular basis. Stay tuned to Breastcancer.org for the latest research results in this area of treatment.