Chemo Therapy

Chemotherapy is treatment with anticancer drugs that may be given intravenously (injected into a vein) or by mouth. The drugs travel through the bloodstream to reach cancer cells in most parts of the body. When used as adjuvant therapy after breast conservation therapy or mastectomy, chemotherapy reduces the risk of breast cancer recurrence. The chemotherapy is given in cycles, with each period of treatment followed by a recovery period. The usual course of chemotherapy lasts between 3 to 6 months.

Chemotherapy can also be used as the main treatment for women whose cancer has already spread outside the breast and underarm area at the time it is diagnosed or spreads after initial treatments. The length of these treatments is not definite, but depends on how much, if at all, the cancer shrinks.

Chemotherapy given before surgery is called neoadjuvant therapy. The major benefit of neoadjuvant chemotherapy is that it can shrink large cancers so that they are small enough to be removed by lumpectomy instead of mastectomy. Another possible advantage of neoadjuvant chemotherapy is that doctors can see how the cancer responds to chemotherapy. If the tumor does not shrink, then different chemotherapy drugs may be substituted. So far, there is no evidence, however, that this improves survival.

In most cases, chemotherapy is most effective as an adjuvant therapy, when combinations of more than one chemotherapy drug are used together. Clinical research studies over the last 30 years have determined which combinations of chemotherapy drugs are most effective. However, the “best” combination may not have yet been discovered, so there continue to be clinical research studies comparing one of today’s most effective treatments against something that may be better.

The most commonly used combinations are:

Cyclophosphamide (Cytoxan), methotrexate (Amethopterin, Mexate, Folex), and fluorouracil (Fluorouracil, 5-FU, Adrucil) [abbreviated CMF]
Cyclophosphamide, doxorubicin (Adriamycin), and fluorouracil [abbreviated CAF]
Doxorubicin (Adriamycin) and cyclophosphamide [abbreviated AC]
Doxorubicin (Adriamycin) and cyclophosphamide followed by paclitaxel (Taxol) or docetaxel (Taxotere) (abbreviated AC  T) or docetaxel concurrent with AC (abbreviated TAC)
Doxorubicin (Adriamycin), followed by CMF
Cyclophosphamide, epirubicin (Ellence), and fluorouracil with or without docetaxel

Other chemotherapy drugs used for treating women with advanced breast cancer include vinorelbine (Navelbine), gemcitabine (Gemzar), and capecitabine (Xeloda).

Doctors give chemotherapy in cycles, with each period of treatment followed by a rest period. The chemotherapy is given on the first day of each cycle, and then the body is given time to recover from the effects of chemotherapy. The chemotherapy drugs are then repeated to start the next “cycle.” The time between giving the chemotherapy drugs is generally every 2 weeks, or every 3 weeks. Some drugs are given more often. These cycles generally last for a total time of 3 to 6 months when given as adjuvant therapy, depending on the drugs used.

The side effects of chemotherapy depend on the type of drugs, the amount taken, and the length of treatment. Temporary side effects might include fatigue, nausea and vomiting, loss of appetite, hair loss, and mouth sores. Changes in the menstrual cycle may be temporary or permanent. Because chemotherapy can damage the blood-producing cells of the bone marrow, patients may have low blood cell counts. This can result in an increased chance of infection (due to a shortage of white blood cells), bleeding or bruising after minor cuts or injuries (due to a shortage of blood platelets), and fatigue (due to low red blood cell counts).

There are very effective remedies for many of the temporary side effects of chemotherapy. For example, there are several drugs that can prevent or reduce nausea and vomiting. A group of drugs called growth factors can help the patient's bone marrow recover after chemotherapy and can treat problems caused by low blood counts.

Premature menopause (not having any more menstrual periods) and infertility (not being able to become pregnant) are potential permanent complications of chemotherapy. The older a woman is when she receives chemotherapy, the more likely it is that she will become infertile or menopausal as a result. This can also lead to rapid bone loss from osteoporosis.

Adriamycin (doxorubicin) may cause permanent heart damage if used for a long time or in high doses, but doctors carefully control the dose of this drug. They use echocardiograms and other heart tests in order to monitor the heart and will stop the medication at the first sign of damage.

Another side effect of chemotherapy is "chemo brain." Many women who have received chemotherapy for breast cancer will experience a slight decrease in mental functioning. There may be some difficulty in concentration and memory. This may last a long time, but it rarely interferes with a woman’s ability to do intellectual tasks.

Very rarely, 1 to 2 years after treatment for breast cancer, certain chemotherapy drugs may cause acute myeloid leukemia, a life-threatening cancer of white blood cells. Chemotherapy's benefits in preventing many breast cancers from coming back and in saving lives from breast cancer far exceed the risk of this serious but rare complication.

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