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Chemotherapy

The use of extensive surgery does not always rid the body of cancer cells. Cancer cells sometimes metastasize, or break away from the tumor, even in the early stages of tumor development, and spread to other parts of the body, where they can form new tumors. Often, these cancer cells are "hidden" (cannot be detected by physical examination or imaging).

Chemotherapy is the use of cytotoxic (cell-killing) drugs to kill cancer cells. Chemotherapy is often used in combination with surgery or radiation therapy to treat cancer:

• To kill any hidden cancer cells that may have spread to other parts of the body;



• When the cancer has spread;



• When the cancer has come back (recurred); or



• To prevent the cancer from recurring.

When chemotherapy is used in addition to the main treatment to increase the chances of curing the disease or keeping it in check it is referred to as adjuvant therapy.

In some instances, chemotherapy drugs are given before surgery to shrink a tumor. This type of treatment is called neoadjuvant therapy. Neoadjuvant therapy can be used to:

• Shrink tumors that are too large to remove completely by surgery;



• Shrink large tumors to the extent that breast conservation surgery is possible.

Administration of Chemotherapy

Chemotherapy drugs can be given in pill or liquid form by mouth (orally) or through a vein (intravenously) and can reach cancer cells that have metastasized to other parts of the body. Drugs can be given intravenously (IV) as a rapid injection or dripped in slowly over a longer period.

Chemotherapy is given in cycles - a treatment period followed by a recovery period - to give the normal cells in the body time to recover between treatments. The full course of therapy generally takes three to six months to complete. The actual administration of chemotherapy may take a few minutes or several hours, depending on the drug or combination of drugs being used.

How Chemotherapy Works

All living tissue is composed of cells that grow, divide, and die throughout a person's lifetime. After reaching adulthood, the growth of new cells is limited to replacement of worn-out or dying cells or to the repair of injured cells. The cell cycle is a series of steps through which both normal cells and abnormal cancer cells grow and reproduce to form two new cells. There are five phases to the cell cycle.

Chemotherapy drugs work only on actively reproducing cells by interfering with various phases of the cell cycle, so that the cells can't divide, or are damaged and cannot repair themselves. This cell cycle is important to physicians in planning which chemotherapy drugs to use and how often doses of each drug should be given.

Although chemotherapy drugs attack reproducing cells, they do not distinguish between cells of normal tissues and cancer cells. The damage to normal cells can result in side effects, such as nausea and vomiting, fatigue, loss of appetite, and loss of hair. Administration of chemotherapy involves a balance between destroying the cancer cells, to cure or control the disease, and sparing the normal cells, to minimize side effects.

There are a number of chemotherapy drugs that have been approved for use by the Food and Drug Administration for the treatment of breast cancer. Chemotherapy drugs are often given in combinations of two or more to provide more effective treatment. The drug or combination of drugs to be used for each patient will be determined by the physician and other health care professionals based on the type and stage of the cancer and the overall medical condition of the patient.

Side Effects of Chemotherapy

Chemotherapy drugs are made to kill fast-growing cancer cells, but they also can affect normal, healthy cells. Damage to healthy cells is the cause of side effects. The side effects of chemotherapy occur most often in bone marrow, the gastrointestinal or GI tract, the reproductive system, and hair follicles.

The specific side effects of chemotherapy depend on the type of drug used, the dosage, and the length of treatment. Most side effects are temporary and last for varying amounts of time. There are a number of effective medications that prevent or reduce some of the side effects. A woman should discuss the potential side effects of her chemotherapy regimen with the physician before beginning treatment to know what she should expect and when she should seek further medical care for severe or unexpected side effects.

The prospect of chemotherapy can be very frightening because of the expectation that chemotherapy always causes extremely unpleasant side effects. It is important to note that, although some women will experience severe side effects, not all women will experience every side effect, and some women get few, if any. In addition, the severity of side effects varies greatly from person to person. Finally, there are ways to effectively manage side effects.

The most common, temporary side effects of chemotherapy include:

• Nausea and vomiting - there are a number of effective medications that can prevent or reduce nausea and vomiting.



• Hair loss - not all chemotherapy drugs cause hair loss and hair lost to chemotherapy always grows back. The reason hair loss occurs is that chemotherapy temporarily slows down hair production in the follicle. Some women will buy a wig to have available before beginning chemotherapy; others use attractive scarves or turbans.



• A listing of some companies that specialize in chemotherapy-related hair loss products can be found in Breast Cancer Resources.



• Fatigue - high doses of chemotherapy can cause fatigue, especially on the first day after each treatment. Women should adjust their schedule to allow sufficient time for rest when beginning a chemotherapy treatment cycle.



• Loss of appetite - good nutrition is very important to fight cancer and retain strength, so it is important to maintain adequate food intake, especially of proteins and fluids.

Less common, temporary side effects can include:

• Bone marrow suppression - Bone marrow, which produces red blood cells, white blood cells and platelets in the blood, can be damaged by chemotherapy, leading to lower blood cell counts. Reduced red cells can cause anemia. Reduced platelets can lead to bleeding and easily-formed bruises. Reduced white cells can lead to infection, because white blood cells are needed by the body to fight off infections.



• Sores in the mouth - The mouth, stomach, and intestines are lined with rapidly-dividing cells. Chemotherapy drugs can affect these organs, leading to mouth sores and GI problems. Some patients find frozen juices and ice cream to be very soothing to mouth sores.



• Intestinal problems, such as diarrhea. - Women should discuss this side effect with the physician; however, some women have found eating smaller, more frequent meals and avoiding high fiber foods to be helpful.

Change in the menstrual cycle is a side effect that can be temporary or permanent. In some women, premature menopause (permanent ceasing of menstrual periods) or infertility (the inability to become pregnant) can be a permanent side effect of chemotherapy. In some rare instances, chemotherapy can cause permanent heart damage.

This website provides general information only. A physician should be contacted if you need any medical advice or if medical decisions need to be made.