- What is Chemotherapy?
- Chemotherapy Regimens
- Potential Side Effects of Chemotherapy
- Coping with Side Effects of Chemotherapy
- High-Dose Chemotherapy/Bone Marrow Transplants/Stem Cell Rescues
- Additional Resources and References
This section is intended to provide general information on chemotherapy for breast cancer patients and to discuss a variety of possible side effects of chemotherapy drugs. Because chemotherapy regimens are individually tailored, the types of drugs administered and their side effects will vary considerably. While this article discusses many of the side effects of chemotherapy in detail, it is important to note that the majority of the side effects associated with chemotherapy are temporary and only occur during or immediately after treatment. In the vast majority of cases, the benefits of treating cancer with chemotherapy far outweighs the risks or inconveniences of any side effects. Chemotherapy is only one possible treatment for breast cancer and may be used in addition to surgery or other treatments. Patients should discuss all aspects of chemotherapy and breast cancer treatment with their physician or cancer treatment team.
Chemotherapy involves using anticancer drugs to help control or prevent the growth of cancerous tumors. Chemotherapy is often used as an adjuvant (supplemental) therapy in addition to other treatments, such as surgery or radiation therapy, which are designed to achieve local (breast/chest) control of the cancer. Normally, chemotherapy is administered through a semipermanent catheter (a flexible tube) implanted into a large vein, or by a smaller, temporary, intravenous catheter placed into the smaller veins in the arm or hand. Some chemotherapy drugs are administered orally in form of pills or liquid. Chemotherapy may also be given intramuscularly (injected in the muscle), under the skin, topically (on the skin), or injected locally into the cancer area.
Chemotherapy may be used to:
- cure cancer
- stop cancer from spreading to other parts of the body
- slow cancer growth
- kill cancer cells
- relieve symptoms of cancer
Chemotherapy is a systemic form of treatment; that is, it is distributed throughout the bloodstream, affecting tissues and organs in the entire body. In this way, chemotherapy is different from local treatments such as surgery or radiation therapy, which only target specific parts of the body. Both local and systemic treatments are used to provide optimal cancer control, and the approach is tailored to the individual patient.
Breast cancer patients who undergo chemotherapy may be given one drug or a combination of two or more drugs during treatment. Most physicians believe that combination chemotherapy (administering two or more drugs) is most effective for breast cancer patients because combination therapy has been shown to provide better cancer cell control with lower doses of individual drugs. With combination chemotherapy, better results may be achieved while causing fewer of the side effects associated with higher doses of an individual drug. At this time, there are over 90 chemotherapy drugs used to treat different types of cancer.
Chemotherapy may be the only treatment a breast cancer patient receives, or it may be given before or after breast cancer surgery or other treatments. Neoadjuvant chemotherapy is the term given to chemotherapy that is administered before surgery to help shrink the size of a cancerous tumor. Neoadjuvant chemotherapy also allows physicians to determine the effectiveness of a particular regimen on a patient's tumor and to monitor the progress of chemotherapy and make adjustments in drugs or dosages if needed.
Adjuvant chemotherapy is the term used to described chemotherapy that is given in addition to local breast cancer treatments, such as surgery. Because chemotherapy after lumpectomy or mastectomy has been shown to significantly reduce the chances of breast cancer recurrence, a panel of national and international cancer experts who convened at the National Institutes of Health Consensus Development Conference on Adjuvant Therapy for Breast Cancer in November 2000 recommended that most women with localized breast cancer be offered chemotherapy.
A chemotherapy regimen is usually tailored specifically to the breast cancer patient. When planning a chemotherapy regimen, physicians and patients consider the patient's age, her overall health, specific elements of her cancer (i.e., stage, grade), other health problems, and past or future treatments. In general, chemotherapy for breast cancer patients is typically given in three to six month courses. These courses may occur daily, weekly, monthly or on some other schedule, depending on the body's response to the drugs. Chemotherapy sessions are not usually continuous; they typically include rest cycles because chemotherapy drugs target both healthy and cancerous cells. Physicians have a variety of ways to monitor the effects of chemotherapy on the patient's cancer, including physical examinations, blood tests, CT scans, MRI scans, and x-rays.
Examples of chemotherapy combinations used to treat breast cancer include:
- cyclophosphamide (Cytoxan), methotrexate (Amethopterin, Mexate, Folex), and fluorouracil (Fluorouracil, 5-Fu, Adrucil) (this therapy is called CMF)
- cyclophosphamide, doxorubicin (Adriamycin), and fluorouracil (this therapy is called CAF)
- doxorubicin (Adriamycin) and cyclophosphamide (this therapy is called AC)
- doxorubicin (Adriamycin) and cyclophosphamide with paclitaxel (Taxol)
- doxorubicin (Adriamycin), followed by CMF
- cyclophosphamide, epirubicin (Ellence), and fluorouracil
(the brand name of the drug is shown in parenthesis)
*Source: American Cancer Society