The term metastatic breast cancer describes an advanced and late-stage breast cancer. Metastatic breast cancer cells have formed extensive tumors within the breast and have gained the ability to travel throughout the body through the bloodstream or lymph vessels. Patients with metastatic breast cancer may experience tumor growth in the breast and surrounding tissue, as well as the bone, lungs, liver or brain. Taxol, a chemotherapy drug, is a common treatment for metastatic cancer, though some forms of cancer can become resistant and unresponsive to taxol treatment. Therapy with a number of others drugs may successfully slow or stop taxol-resistant cancer growth.
Capecitabine
One alternative to taxol is a capecitabine, a chemotherapy drug. According to the National Cancer Society, capecitabine belongs to a class of drugs called antimetabolites. These drugs work by interacting with and inhibiting essential metabolic processes in the cell. Without proper cellular metabolism, the cancer cell cannot perform functions needed to divide and grow. As a result, exposure to capecitabine stops cell proliferation and eventually leads to breast cancer cell death. Since capecitabine is a systemic chemotherapy treatment--it targets cancer cells anywhere in the body--it can effectively treat metastatic breast cancer growing in multiple organs at once. Capecitabine may be administered in combination with other breast cancer therapies to treat breast cancer.
Trastuzumab
Another common treatment for some forms of metastatic breast cancer is trastuzumab, also called Herceptin. Herceptin is an antibody therapy--the drug is a specialized antibody designed to bind specifically to a protein found on the surface of breast cancer cells. Specifically, Herceptin binds to a protein called HER2, a factor that promotes breast cancer cell growth. Some forms of breast cancer contain very high levels of HER2, while normal cells have little or no HER2. When Herceptin binds to and recognizes these cancer cells, the drug stimulates the body's immune system, and the immune system engulfs and kills the breast cancer cell. Since the drug targets HER2, which is specifically located on cancer cells, HER2 destroys the cancer cells while leaving healthy cells intact. Herceptin effectively treats HER-containing metastatic breast cancers, according to Genentech, the drug's developer.
lapatinib
Another possible alternative to taxol in the treatment of metastatic breast cancer is lapatinib. Lapatinib belongs to a family of drugs called kinase inhibitors--they inhibit proteins in the cells called kinases, which normally promote cell growth. Cancer cells typically over activate kinase proteins during the cancer's development, and this over-activity promotes cancer growth. By inhibiting the function of kinases, lapatinib can stop proliferative signals in cancer cells, and therefore slow or stop cancer cell growth. Medline Plus indicates that lapatinib is commonly prescribed in combination with other therapies, such as capecitabine, and can effectively treat metastatic breast cancer after other treatments have failed.
