- 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:
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:
(the brand name of the drug is shown in parenthesis)
Other chemotherapy drugs commonly used for treating women with breast cancer include docetaxel (Taxotere), vinorelbine (Navelbine), and gemcitabine (Gemzar), and capecitabine (Xeloda).
*Source: American Cancer Society
The side effects a breast cancer patient experiences while undergoing chemotherapy vary significantly depending on several factors, including the types of drugs used, their dosages, and the duration of treatment. This section discusses some of the possible side effects that breast cancer patients may experience. Some patients experience few to no negative effects from chemotherapy. In most cases, the benefits of treating cancer with chemotherapy far outweighs the risks or inconveniences of any side effects.
Some chemotherapy drugs may irritate the lining of the stomach or intestines. Examples of drugs that may be more likely to cause nausea or vomiting include cisplatin, cyclophosphamide, doxorubicin, etoposide (high doses), etc. Sometimes, nausea and vomiting occur within a few minutes of or after treatment. At times, patients may experience "anticipatory" nausea, in which symptoms develop before a treatment due to psychological associations. In most cases, drugs may be prescribed to help reduce nausea or vomiting due to chemotherapy. See the Coping with Side Effects of Chemotherapy section for more information.
Hair loss (alopecia) is another fairly common side effect of chemotherapy. Hair loss, which is temporary, may occur in some women because hair follicles are weakened by chemotherapy, causing hair to fall out at a much faster rate than normal. Most patients who experience hair loss will not begin losing their hair until after the second chemotherapy session and will find that it grows back, sometimes with a change in texture, after the chemotherapy is complete. There are several options available for women who lose their hair during chemotherapy, including a variety of wigs and head wear. Click here to learn more about coping with hair loss during chemotherapy.
Low blood cell counts (white and red blood cells) and platelet counts are other possible side effects from chemotherapy. White blood cells are an essential component of the body's immune system. Normal white blood cells counts range between 4,000 and 10,000 white blood cells per cubic millimeter. A low white blood cell count is called leukopenia. There are several types of white blood cells, including neutrophils, which help the body fight infection. Neutropenia is the term used for a sharp decrease in the number of neutrophils. Special guidelines should be followed to avoid infection if this occurs. Neutropenia can usually be treated with agents used to stimulate the immune system and should always be monitored closely by the patient and her treating physician. Click here for more information on neutropenia.
Chemotherapy can also cause a reduction in the number of red blood cells. Normally, the blood has between 4.0 and 6.0 million red blood cells per cubic millimeter. A lack of red blood cells can cause anemia. Anemia is a condition that may be associated with fatigue, dizziness, headaches, irritability, and an increase in heart rate or breathing. Anemia can sometimes be treated with drugs (see the Coping with Side Effects of Chemotherapy section below). In some cases, low blood cells counts may require transfusions.
Low platelet counts can also occur in patients who undergo chemotherapy. The normal range for platelet counts is between 150,000 and 450,000 platelets per cubic millimeter. Patients who suffer from low platelet counts are said to have thrombocytopenia. Symptoms of low platelet counts include the tendency to bruise easily (or develop small and large bruises), to bleed longer than usual after cuts, or to have nosebleeds or bleeding gums. In severe cases, patients with low platelet counts may experience internal bleeding. Platelet transfusions may be necessary in some cases to elevate the number of platelets in the blood. Drugs such as operlvekin (brand name, Neumega) may also be prescribed in some cases.
Cancer patients who undergo chemotherapy should also be aware that chemotherapy drugs can cause infertility or premature menopause. The closer a woman is to menopause when she undergoes chemotherapy, the more likely she is to experience premature menopause. Women who are given chemotherapy often experience symptoms of menopause, such as hot flashes, vaginal dryness, and irregular menstrual cycles. These symptoms are not uncommon and can often be managed adequately with many different regimens. Any of these changes should be discussed with the physician or nurse administering the chemotherapy. Chemotherapy drugs can also cause birth defects; therefore, it is essential that women who are able to conceive use birth control during chemotherapy. Couples may also wish to discuss banking sperm or eggs prior to chemotherapy if they wish to have children in the future.
Other side effects of chemotherapy may include:
When patients begin tamoxifen or any other chemotherapy regimen, they may experience a "flare" reaction in which bone or tumor pain increases. This may be a sign that the tumor is responsive to the treatment. Supportive measures and pain control are generally offered until the acute "flare" phase subsides. However, patients should discuss any bone pain with their physicians, especially if pain persists.
In addition, certain chemotherapy drugs carry additional risks. For example, the drug doxorubicin (brand name, Adriamycin) can cause permanent heart damage in some patients when taken in high doses over a long period of time. Patients should be tested for heart problems before beginning Adriamycin and should be continuously monitored for developing problems during treatment.
Despite this long list of potential side effects, the benefits of treating cancer with chemotherapy drugs outweighs the risk of complications for most women, and effects are often tolerable with proper care and rest.
Some patients who experience certain side effects of chemotherapy may be prescribed medications to counteract these effects. For example, several drugs are now available for use alone or in combination to help reduce nausea and vomiting or fatigue, a few of the most common side effects of chemotherapy. Some of these drugs include:
Patients who experience low blood cells counts during chemotherapy may also be given medications to help raise blood cell or platelet counts. For example, patients who suffer from neutropenia, a decrease in the number of neutrophils (a type of white blood cell), may be given certain growth factors, such as the granulocyte-macrophage colony stimulating factor (GM-CSF, generic name sargramostim, brand name Leukine) or granulocyte colony stimulating factor (G-CSF, generic name filgrastim, brand name Neupogen). Click here to learn more about neutropenia.
Breast cancer treatment with high doses of chemotherapy remains a controversial subject among members of the medical community. In January 2000, a breast cancer researcher from South Africa admitted to falsifying the results of a study that showed high-dose chemotherapy followed by bone marrow transplants benefits patients with advanced breast cancer. A team of American scientists became suspicious about the results of Dr. Werner Bezwoda's study after four similar studies showed no benefit. However, other studies have shown high-dose chemotherapy to be a promising treatment for some patients with advanced breast cancer. Currently, the treatment is only available to eligible patients in closely monitored clinical trials.
Because prolonged high doses of chemotherapy may damage bone marrow cells, which in turn can result is dangerously low blood cell counts, physicians may need to perform bone marrow transplants (or stem cell rescues) on patients who are given high-dose chemotherapy.
If a bone marrow transplant seems likely, physicians will take a sample of bone marrow from a bone in the leg or pelvis before high-dose chemotherapy is begun. These extracted stem cells are immediately frozen for preservation. Next, the patient will begin receiving high-dose chemotherapy (which may destroy the body's remaining bone marrow). After chemotherapy is completed, the preserved bone marrow cells are thawed and re-injected into the body where they will multiply. Bone marrow is responsible for the production of white and red blood cells.
Recently, physicians have been performing autologous stem cell rescues after high-dose chemotherapy instead of bone marrow transplants. Autologous stem cell rescues involve using the patient's own blood to obtain stem cells, the precursors of all blood cells. Stem cells will regenerate bone marrow function in the patient after high-dose chemotherapy. Studies have shown that stem cell rescue may be associated with lower mortality rates than traditional bone marrow transplants.
Chemotherapy can be very effective at treating cancer and preventing a recurrence of breast cancer. Researchers have been making significant advances in the field of chemotherapy and cancer treatment. As research continues, physicians predict that new chemotherapy drugs with greater effectiveness and fewer side effects will become common. Also, more drugs used to counteract the side effects of chemotherapy are being developed. An expert panel that 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 to help prevent a recurrence of breast cancer. Women with breast cancer are encouraged to discuss chemotherapy with their physicians.
Updated: October 18, 2009