Classes of Breast Cancer Drugs

Classes of Chemotherapy Drugs Used to Treat Breast Cancer

Chemotherapy drugs—anthracyclines:

Anthracyclines are a certain group of chemotherapy drugs. While anthracyclines can be very effective against breast and other cancers, they pose a risk of cardiotoxicity (severe heart problems) and therefore, they are typically used in limited doses. Patients should also be closely monitored for any heart problems during treatment. Anthracyclines work by deforming the DNA structure of cancer cells and terminating their biological function. The drugs Adriamycin (generic name, doxorubicin) and Ellence (generic name, epirubicin) are examples of anthracyclines used to treat breast cancer. Anthracyclines are commonly used in combination with other chemotherapy drugs to help decrease the risk of side effects.

Chemotherapy drugs—taxanes:

Taxanes are a certain group of chemotherapy drugs that prevent cancer cells from dividing. Taxanes affect microtubules of cells, which are normally formed when cells divide. Normally, once cells stop dividing, the microtubules are broken down. However, taxanes stop microtubules from breaking down, thereby "clogging" cancer cells with microtubules so they cannot divide. The drugs Taxol (generic name, paclitaxel) and Taxotere (generic name, docetaxel) are examples of taxanes used to treat breast cancer. Taxanes are often used in combination with other chemotherapy agents.

Chemotherapy drugs—alkylating agents:

Alkylating agents are a certain group of chemotherapy drugs that target the DNA of cancer cells to prevent the cells from growing or reproducing. Alkylating agents attack cancer cells in all phases. The drug Cytoxan (generic name, cyclophosphamide) is a common alkylating agent used to treat breast cancer. Cytoxan is typically used in combination with other chemotherapy drugs.

Drugs Used to Treat Bone Metastases

When breast cancer spreads past the breast and axillary (armpit) lymph nodes, it often spreads first to the bone. These breast cancer tumors in the bone are called "bone metastases." As advanced breast cancer dissolves portions of bone, a variety of problems can occur. Bone metastases can cause pain, decreased activity, and potentially severe problems such as fractures. Other complications that can arise from bone metastases include the surgical treatment for fractures, hypercalcemia (abnormally high levels of calcium), and spinal cord compression (vertebral damage due to pressure on the spinal cord). A class of drugs called bisphosphonates can beneficial for breast cancer patients whose cancer has spread to the bone.

Bisphosphonates are currently used to help treat osteoporosis, a degenerative bone disease affecting mainly post-menopausal women. In patients with osteoporosis, the bone loses a significant portion of its density, greatly increasing the risk of serious fractures.

Types of bisphosphonates that may be helpful in treating bone metastases include:

• Didronel (generic name, etidronate)
• Bonefos, Clostoban, Loron, Ostac (generic name, clodronate)
• Skelid (generic name, tiludronate)
• Fosamax (generic name, alendronate)
• Zometa (generic name, zoledronate)

Click here for profiles of individual breast cancer drugs.

Updated: November 12, 2007