This page discusses the use of chemotherapy for the treatment of breast cancer. For a thorough review of chemotherapy for cancer treatment, please see the chemotherapy treatment monograph .

Chemotherapy is the use of drugs to treat cancer. The drugs may be used to kill cancer cells that have spread beyond the breast (metastasized) or to shrink existing tumors in preparation for cancer surgery (in this case called “neoadjuvant chemotherapy”). In order to attack cancer cells that may have traveled to other parts of the body, the drugs work systemically. This means they are either absorbed orally or injected intravenously to treat distant sites in the body. Often, chemotherapy is given in conjunction with other treatment regimens, such as radiation therapy, hormonal therapy, and/or surgery.

Most chemotherapy is administered through the vein (intravenously or by IV), although some types may be given orally. If you are receiving intravenous chemotherapy, you will need to have it administered in a doctor’s office, hospital, or clinic. The visits usually last from 2–6 hours, but this may also include consultation with your health care provider.

Treatments will vary according to what type of drug(s) you take. The number of cycles of therapy differs with the clinical situation and the type of drugs. Doses of chemotherapy may be given weekly up to every 4 weeks. Your medical oncologist will tell you how many cycles or courses of chemotherapy are best for you.

Chemotherapy Drugs Used for Breast Cancer

There are over 35 chemotherapy drugs used to treat breast cancer. Most breast cancer regimens combine one or more chemotherapy drugs together to mount a stronger attack on cancer cells. The most commonly used drugs include:

  • Doxorubicin (Doxil, Adriamycin)
  • Epirubicin (Ellence)
  • Methotrexate
  • Cyclophosphamide (Cytoxan).
  • 5-fluorouracil
  • Docetaxel (Taxotere)
  • Paclitaxel (Taxol, Paxene)
  • Gemcitabine (Gemzar) 
  • Vinorelbine (Navelbine)
  • Capecitabine (Xeloda)

The chemotherapy combination regimens commonly used to treat breast cancer include the following:

  • CA: A combination of cyclophosphamide and doxorubicin(Adriamycin). This combination is given through an IV on the first day, followed by 20 days of rest. The cycle is repeated four times.
  • CAF (FAC): A combination of cyclophosphamide, doxorubicin (Adriamycin), and 5-fluorouracil. All are usually given through an IV the first day, although cyclophosphamide may be given orally on days 1-14 instead. Doxorubicin and 5-fluorouracil may also be given on the 8th day, followed by 20-27 days of rest.
  • CMF : A combination of cyclophosphamide, methotrexate, and 5-fluorouracil. This combination is given through an IV on days 1 and 8. Cyclophosphamide can be given intravenously on day 1 and 8 or as oral pills on days 1-14, followed by 2 weeks of rest. The cycle is repeated six times.
  • Taxol or Taxotere : This drug is given by IV weekly or every three weeks, usually for 12 weeks, or more if there is reason to continue.

Side Effects and Possible Complications

Most chemotherapy does result in certain long- and/or short-term side effects, which are caused by the destruction of normal cells in addition to cancer cells. The side effects will depend on the type of chemotherapy you receive, as well as how many cycles you receive and how often.

The most common chemotherapy-associated side effects are:

  • Nausea and vomiting
  • Fatigue or extreme tiredness
  • Hair loss
  • Low blood cell counts, which may result in an increased susceptibility to infection or increased risk of bleeding
  • Premature menopause

Late complications from chemotherapy are rare but may include damage to the heart (cardiomyopathy) or damage to the bone marrow resulting in myelodysplastic syndrome (MDS) or leukemia .

For more information on chemotherapy, including how to manage the side effects, please see the chemotherapy treatment monograph .