Treatment Guidelines | Surgery | Radiation Therapy | Chemotherapy | Drug Therapies

Drug therapies may be used alone or in conjunction with other treatments, depending on the type and stage of cancer being treated.

There are two categories of drugs used to treat breast cancer:

Hormonal therapy refers to use of drugs that block the effects of estrogen or lower or eliminate estrogen levels. Estrogen is a hormone produced by women's ovaries that promotes the growth of about 2 out of 3 breast cancers. Tamoxifen and toremifene are anit-estrogen drugs used,to temporarily block estrogen receptors on breast cancer cells.

Tamoxifen is used as an adjuvant therapy in women with estrogen-positive breast cancers. Women generally take tamoxifen for 5 years following surgery. This treatment can reduce the chances of the cancer coming back by about half. Tamoxifen can also be used to treat metastatic breast cancer, as well as to reduce the risk of developing breast cancer in women at high risk.

Toremifene is used mainly in post-menopausal women with advanced, estrogen-positive cancers.

Fulvestrant (Faslodex): Fulvestrant is a drug that eliminates estrogen receptors. It is sometimes effective even if the breast cancer is no longer responding to tamoxifen.and is currently approved for use in post-menopausal women with advanced breast cancer that no longer responds to tamoxifen or toremifene.
Aromatase inhibitors stop estrogen production in post-menopausal women and are used to treat both early and advanced breast cancer. They work by blocking an enzyme (aromatase) responsible for making small amounts of estrogen in post-menopausal women. The drugs cannot stop estrogen production in pre-menopausal women, so they are only effective in post-menopausal women. These drugs are taken daily as pills.

Several studies have compared these drugs with tamoxifen as adjuvant hormone therapy in post-menopausal women. Using these drugs, either alone or after tamoxifen, has been shown to better reduce the risk of cancer recurrence compared to using just tamoxifen alone for 5 years

Targeted therapy refers to drugs that target gene changes in cells that cause cancer. A growth promoting protein known as HER2/neu is present in small amounts on the surface of normal breast cells and most breast cancers. In approximately one out of five of all breast cancers, an excessive amount of this protein is present, promoting the aggressive growth and spread of breast cancers. The drug trastuzumab can block the HER2/neu protein from stimulating breast cancer cell growth and may cause the immune system to attack the cancer more aggressively. Trastuzumab is also used to shrink some breast cancer metastases that do not respond to chemotherapy or that recur after chemotherapy.

Lapatinib (Tykerb): Lapatinib is another drug that targets the HER2 protein. This drug is used in women with advanced HER2-positive breast cancer that is no longer helped by chemotherapy and trastuzumab. It is also being studied as an adjuvant therapy in HER2-positive patients. cancer.