Chemotherapy is used in the treatment of cancer using cytotoxic (toxic to cells) medicines. Cancer cells are cells in our body that divide and multiply quickly in an uncontrolled fashion.

The aim of chemotherapy is to kill the cancer cells, often by directly targeting cell growth cycles, while doing the least possible damage to normal cells. Cancer cells can form a lump or mass that keeps getting bigger and bigger (local spread) and can also travel to other parts of the body through the lymphatic system and bloodstream (metastatic spread).

On this page, you can find the following information:

How does chemotherapy work?

Chemotherapy can travel through the bloodstream and kill cells in the body that grow quickly (such as cancer cells). They also kill fast-growing normal cells, eg, those that make up our blood, hair growth and the lining of the gastrointestinal tract. This is why they can cause side effects throughout the body.

Fortunately, our bodies are good at healing and growing. Even when normal cells are damaged, they can repair and grow again. Cancer cells lose their ability to control growth and repair, therefore when damaged they are less likely to grow back. This is why chemotherapy can slow or stop the spread of cancer.

What does chemotherapy do?

Depending on your type of cancer and how advanced it is, chemotherapy can:

  • Cure cancer when chemotherapy destroys cancer cells to the point that your doctor can no longer detect them in your body and they won't grow back. Sometimes cure is achieved with a mix of chemotherapy and/or surgery or radiotherapy.
  • Control cancer when chemotherapy keeps cancer from spreading, slows its growth, or destroys cancer cells that have spread to other parts of the body.
  • Ease cancer symptoms when chemotherapy shrinks tumours that are causing pain or pressure.

How is chemotherapy given?

Sometimes 1 type of chemotherapy drug is given by itself, either as tablets or capsules, or in a drip (intravenous or IV infusion). More often, 2 or more medicines are given together.

In cancers where many intravenous (IV) chemotherapies are given or blood tests will need to be taken, a central line may be put in to help with these. A central line can be a long intravenous line inserted through a vessel in your arm or chest, or may be a device placed in a large vessel in the chest to allow easy access during your treatments. These lines can be used long term, and are often cleaned and redressed by nurses.

Chemotherapy doesn't get into the brain, spinal cord or fluid around the brain and spinal cord very well so, for a few cancers, the medicines are inserted into the base of the spine through a process called lumbar puncture.

Is chemotherapy painful?

Having chemotherapy doesn't usually hurt. If you have a drip (IV) you may 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.

Medicines to help with pain, nausea and swelling are often given with chemotherapy so any side effects can be managed well throughout your treatments.  

Will I have to stay in hospital?

Most people have their chemotherapy as an outpatient. Usually you have to spend a few hours at the hospital for each treatment. At your treatment, it is likely you will have a blood test first, or on the day before. Your doctors and nurses will check if you are well enough and check the results 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 receive financial support for travel and accommodation. Talk to your treatment team to arrange this. Where possible, you can get support to bring whānau and support people to stay with you.

How is the type of chemotherapy chosen?

The type of treatment that your specialist chooses for you depends on:

  • what type of cancer you have
  • how far it has spread
  • 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.

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 medicines 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 treatment last?

Your treatment could last several weeks or several months. You will probably get one dose of treatment at a time or over a few days, and then you will be given a rest before having the next treatment. Treatments are usually given in ‘cycles’ – usually 1–2 weeks of treatment at a time, followed by 2–4 weeks break, before starting again. Spacing out your treatment in this way gives your body a chance to recover from any side effects.

What blood tests will I need? 

This will be decided by the team treating you, but it is likely you will have regular blood tests before and during each treatment. These may test your blood cell count, liver and renal function and also check markers of your response to chemotherapy. You need to have blood counts because chemotherapy 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 chemotherapy or give you additional treatment that boosts blood counts.

Chemotherapy and other treatments

Chemotherapy can be used alone for treatment. Sometimes it is started after surgery, when a tumour or bulk of the cancer is removed. In this way, the chemotherapy kills any cancer cells that were not removed during surgery. In other cases chemotherapy is given before surgery or radiation, to make the cancer smaller, so that these treatments are likely to work better.

Chemotherapy and other medicines

Before you start chemotherapy, give your specialist a list of all the medicines and supplements that you are taking, including occasional paracetamol (eg, Panadol), aspirins, anti-inflammatories (eg, Nurofen), vitamins, or treatments from herbalists, naturopaths, homoeopaths, etc.

If you want to take any new medicines while having chemotherapy, check with your GP or specialist about these before you begin taking them. Some chemotherapy does not mix well with other medicines or there might be a better time in your treatment to begin them.

Can I drink alcohol?

It is usually fine to drink a little alcohol during treatment, but check with your specialist first – some chemotherapy doesn't mix well with alcohol or you may need to avoid alcohol at certain points during the treatment cycle. 

Can I drive?

You will probably find it best to get someone to drive you to and from hospital for the first treatment, as you might not feel well enough to drive. If you feel okay to drive after your first treatment, you will probably be fine to do so for following appointments.

If you live far away from the hospital, you should arrange for someone to drive you or ask about transport options.

Does chemotherapy cause cancer?

Very rarely, some people who have chemotherapy may get another form of cancer much later in life. However, 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 GP or specialist.

Caring for yourself during chemotherapy

In terms of carrying out other activities while being treated, do only what you feel comfortable doing. You may find you can mostly 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 treatments.
  • Look to those who can support you and plan to do as little as possible. Put your needs and wishes first.
  • Most people keep working during their chemotherapy 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, whānau and friends and work out what suits you. There may even be more flexible work arrangements if you make a time to talk about it. Try to not push yourself to do too much.


There are a number of support services available, talk to your treating team for further recommendations.

How can we help? Cancer Society of NZ, 2022
Emotions and cancer Cancer Society of NZ, 2022
Questions you may wish to ask Cancer Society of NZ, 2022 
Questions to ask your doctor about chemotherapy Cancer Society of NZ, 2022
Find a cancer hospital/service near you Healthpoint, NZ
Cancer Ministry of Health NZ, 2022
National Travel Assistance Scheme Te Whatu Ora (Health New Zealand)
Cancer support Health Navigator
Patient Information sheets eviQ, Australia

Credits: Health Navigator Editorial Team. Reviewed By: Health Navigator Editorial Team Last reviewed: 04 Oct 2022