Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. They work by disrupting the growth of cancer cells. The chemotherapy drugs are usually given by injection into a vein (intravenously). As the drugs circulate in the bloodstream, they can reach cancer cells all over the body.

Our section on chemotherapy discusses the treatment and its side effects in more detail. We also have information about individual drugs and their particular side effects.

Chemotherapy may be used before or after surgery or radiotherapy to try to make them more effective. Sometimes chemotherapy may be given at the same time as radiotherapy (a treatment known as chemo-radiotherapy), as they can be more effective when given together.

Chemotherapy may also be given to people whose cancer has spread to other parts of the body or whose cancer has come back after radiotherapy. It is used for people in this situation to try to shrink and control the cancer and relieve symptoms, or to try to prolong a good quality of life.

Side effects

Chemotherapy can cause some temporary side effects. These will gradually disappear after the treatment has finished. You may have some of those listed below:

Lowered resistance to infection (neutroplasia)

Chemotherapy can temporarily reduce the production of white blood cells in your bone marrow, making you more prone to infection.

This effect can begin about seven days after treatment has been given and your resistance to infection usually reaches its lowest point about 10–14 days after chemotherapy. Your blood cells will then increase steadily and will usually have returned to normal before your next cycle of chemotherapy is due.

You should contact your doctor or the hospital straightaway if:

• your temperature goes above 38ºC (100.5ºF)
• you suddenly feel unwell (even with a normal temperature).

You will have a blood test before having more chemotherapy, to make sure that your cells have recovered. Occasionally it may be necessary to delay your treatment if your blood count is still low.

Bruising or bleeding

The chemotherapy can reduce the production of platelets, which help the blood to clot. Let your doctor know if you have any unexplained bruising or bleeding, such as nosebleeds, blood spots or rashes on the skin, and bleeding gums.

Anaemia (low number of red blood cells)

While having chemotherapy you may become anaemic. This may make you feel tired and breathless. Blood transfusions may be given if you become anaemic due to chemotherapy.

Feeling sick (nausea) and vomiting

Your doctor can prescribe very effective anti-sickness (anti-emetic) drugs to prevent or greatly reduce nausea and vomiting. If the sickness is not controlled, or continues, tell your doctor, who can prescribe other anti-sickness drugs which may be more effective.

Hair loss

Not all chemotherapy drugs cause hair loss. Hair may be lost completely or may just thin. If you lose your hair, it should grow back within 3–6 months.

Sore mouth and small mouth ulcers

Regular mouthwashes are important and your nurse will show you how to do these properly. If you don't feel like eating meals, you can supplement your diet with nutritious drinks or soups. A wide range of drinks is available and you can buy them at most chemists. You can ask your doctor to refer you to a dietitian for advice about your diet.

Tiredness

Chemotherapy affects different people in different ways. Some are able to lead a normal life during their treatment, while many find they become very tired and have to take things more slowly. Just do as much as you feel like and try not to overdo it.

Although they may seem hard to bear at the time, it may help to remember that these side effects are temporary and will usually disappear, in time, once your treatment is over.