1. Four Categories
There are four main categories of breast cancer drugs. Each one works in a different way depending on the individual taking the drug. Most breast cancers need estrogen to survive and divide, so many of the drugs work to prevent estrogen from getting to cancer cells. Other breast cancer drugs include chemotherapy drugs and drugs used specifically when breast cancer spreads into the bone. Some cancer patients use a combination of different drugs to fight their particular type of breast cancer. Each type of drug in the four main categories has a different effect on cancer cells and their causes, but all work to stop the growth of breast cancer tumors.
2. Estrogen Receptor Drugs
Some breast cancers need estrogen to survive. SERMS are breast cancer drugs that starve cancer cells of estrogen. When the drugs bind to estrogen receptors in breast cancer cells it prevents them from getting more estrogen. The reason SERMs do this is because they mimic real estrogen and make the body respond as it would to estrogen. As the SERMs bind to the estrogen receptor cells they actually block real estrogen from the cancer cells. These drugs include: Tamoxifen, Evista (raloxifene) and Fareston (toremifene).
3. Estrogen Production Inhibitors
Since many breast cancers feed on estrogen, stopping the supply is one way to fight the disease. Estrogen production inhibitors, or Aromatase Inhibitors, keep the adrenal gland from producing estrogen. These inhibitors actually bind to the enzyme that allows the body to produce estrogen, blocking its production. Aromatase inhibitors are: Megace (megestrol), Femara (letrozole), Aromasin (exemestane) and Arimidex (anastrozole).
4. Protein Binders
Another category of breast cancer drugs are biological response modifiers. Biological response modifiers interact with certain breast cancer proteins and bind to them. These modifiers prevent breast cancer cells from growing. Biological response modifiers work only in those patients who test positive for the HER2 protein. About 30 percent of breast cancer patients have extra HER2 protein which often means a more aggressive type of breast cancer. Herceptin (trastuzumab) is a biological response modifier.
5. Hormone Therapies
Certain hormonal therapies also treat breast cancer. These hormonal therapies work on breast cancer cells that need estrogen to survive. They are Zoladex (goserelin acetate) and Faslodex (fulvestrant). Zoladex is an estrogen blocker and prevents the release of estrogen in patients with breast cancer. Fasloden destroys estrogen receptors in cancer cells and seems to work in women who are resistant to Tamoxifin.
