What is chemotherapy?

Chemotherapy is the treatment of cancer using anti-cancer (cytotoxic) drugs. The aim is to kill cancer cells while doing the least possible damage to normal cells.

How does it work?

Chemotherapy stops cancer cells from dividing and multiplying. It travels through the bloodstream and kills cancer cells in different parts of the body. It can also affect normal cells. Fortunately, most cells in the body are not growing rapidly and so chemotherapy doesn't affect them.

Chemotherapy is more likely to affect the cells in the body that grow quickly, which is why some people lose their hair, have a sore mouth or have a fall in the number of blood cells.

Even when normal cells are damaged, they grow again. Damaged cancer cells are less likely to grow back.

Targeted treatment

Recently, new drugs have become available that are more specifically directed at cancer cells and the structures essential for their growth and survival than existing chemotherapy drugs. They are now being used in the treatment of a few kinds of cancers, and some promising new compounds are being developed.

Through better targeting, these newer drugs should be more effective against cancers resistant to conventional chemotherapy and cause fewer unpleasant and dangerous side effects on health and normal cells.

A diagnostic technique known as microarray analysis can be used to study the genetic composition of cancers. It may soon be possible to predict accurately
how a cancer will behave and how it will respond to different treatments.

How will I be given chemotherapy?

Sometimes one type of chemotherapy drug is given by itself, either as tablets or capsules, or in a 'drip' (IV infusion). More often, two or more drugs are given together.

You'll probably be given your drugs by injection or drip into a vein, or via a portable infusion pump, although you might be given tablets as well. It is very important that you take your tablets when and how your doctor says. If you are not sure about what to do, ask your doctor or nurse to write down instructions for you.

Drugs don't get into the brain, spinal cord or fluid bathing the brain and spinal cord very well, so for a few cancers, the drugs are inserted into the base of the spine through a process called lumbar puncture.

How will my doctors decide on the type of chemotherapy?

The type of treatment that your specialist chooses for you depends on what type of cancer you have, how far it has spread and your general health. Chemotherapy has been used for many years, and new and better treatments are being discovered all the time, so your doctors will select the best treatment for you and your type of cancer.

Because everyone is different, treatments are designed for the individual. Your doctors will keep a close eye on you during your treatment. You may have blood tests, x-rays and scans to see how you are doing.

If necessary, your doctors will change your drugs or how they give them to you. Sometimes they will stop the treatment early or continue it for longer than planned. It all depends on how your body and the cancer respond to the treatment.

How long will my treatment last?

Your treatment could last several weeks or several months. You'll probably get one dose of treatment at a time or over a few days, and then you'll be given a rest before having the next treatment. Treatment cycles are usually 2-4 weeks apart. Spacing out your treatment in this way gives your body a chance to recover from any side effects.

Blood tests

Before you have each treatment, a blood sample will be taken. This test (known as a blood count) measures the different cells in your blood. You need to have blood counts because chemotherapy drugs can lower blood cell levels.

If any part of your blood count is too low, your doctors might give you a longer time between treatments, they may change your drugs or give you additional treatment that boosts blood counts.

Will it cure me?

Chemotherapy can cure some types of cancer. Sometimes it does this on its own, and sometimes when used with surgery or radiation therapy. At other times, chemotherapy controls your cancer by stopping it growing or by making it shrink. This treatment can give you a longer life or can help reduce any problems the cancer is giving you.

Whether or not chemotherapy cures you depends on what sort of cancer you have and its stage. Ask your specialist how chemotherapy will help you.

Use of chemotherapy to help other treatment

Chemotherapy can be used to assist another treatment, such as surgery or radiation therapy; this is called adjuvant chemotherapy. Adjuvant chemotherapy can be given either before or after the main treatment. When given before other treatment, the drugs can be used to make the cancer smaller so that the main treatment can be more effective.

When given after the main treatment, chemotherapy is often used to kill any cancer cells which have not been found but could cause problems later.

Does chemotherapy hurt?

No, not usually. If you have a drip (IV infusion), you'll feel a brief sting as the needle goes in, but then the pain should stop. However, if the pain continues, or starts during the infusion, let the doctor or nurse know immediately.

Will I have to stay in hospital?

Most people have their treatment as an outpatient. Usually you have to spend a few hours at the hospital for each treatment.  This is because you often have to have a blood test first, and your doctors must wait for the result to check your blood count is okay before they can give you the treatment. Some people stay in hospital overnight or for 2 or 3 days.

If you live a long way from the hospital, you will probably be able to stay free of charge or at low cost at a comfortable hostel or motel. Family members can stay (at a reduced rate) in some hostels.

Can I keep working?

Most people keep working during their treatment and arrange time off to go to hospital for each treatment. Some people work part time instead of full time, while others take a few days off around each treatment. Others take an extended break for the whole course of the treatment.

Talk to your employer, family and friends and work out what suits you. Don't force yourself to do too much.

What about other activities?

Do only what you feel comfortable doing. You may find you can go on with your normal life, or that you have to take things much easier. The important thing is to look after yourself during chemotherapy so that your body is strong enough to cope with the drugs.

Don't do anything that you don't need to do. Put your own needs and wishes first.

What about my other medications?

Before you start chemotherapy, give your specialist a list of all the medications that you are taking, including occasional paracetamol, aspirins, anti-inflammatories, vitamins, or treatments from herbalists, naturopaths, homoeopaths, etc.

If you want to take any new medications while having chemotherapy, ask your specialist about these before you begin taking them. Some chemotherapy drugs don't mix well with other medicines.

Can I drink alcohol?

It is usually fine to drink a little alcohol during treatment, but check with your specialist first - some chemotherapy drugs do not mix with alcohol.

Can I drive?

You'll probably find it best to get someone to drive you to and from hospital for the first treatment, as you don't know how you will feel after it. If you feel okay to drive after your first treatment, you'll probably be fine to do so for following appointments.

Does chemotherapy cause cancer?

Some people who have chemotherapy may get another form of cancer much later in life. However, this rarely happens, and it is much more likely that your treatment will either cure you or control your cancer. If this question concerns you, talk it over with your specialist.

Related topics

What side effects might occur with chemotherapy? See Chemotherapy side effects

How does cancer form? For information on cancer and its causes, see What is cancer?, What causes cancer?

What does that term mean? See Cancer glossary

Original material provided by the Cancer Society of New Zealand, 2006. Reviewed by everybody, September 2008.