Chemotherapy is a type of cancer treatment, with medicine used to kill cancer cells. 

It kills the cancer cells by damaging them, so they can't reproduce and spread.

Why chemotherapy is used

Chemotherapy is used if a cancer has spread or if there's a risk that it will. The main aim of treatment may be:

  • to try to cure cancer completely  this is known as curative chemotherapy
  • to help make other treatments more effective  for example, chemotherapy can be combined with radiotherapy (where radiation is used to kill cancerous cells), or it can be used before surgery
  • to reduce the risk of the cancer returning after radiotherapy or surgery 
  • to relieve symptoms  a cure may not be possible for advanced cancer, but chemotherapy may be used to relieve the symptoms and slow it down; this is known as palliative chemotherapy

Less commonly, chemotherapy is used to treat non-cancerous conditions. For example, low doses have been used to treat lupus and rheumatoid arthritis.

How chemotherapy is used

There are many different types of chemotherapy medication, but they all work in much the same way. Depending on the type of cancer you have, you may be treated with one medicine (monotherapy) or with a combination of medicines (combination therapy).

There are several ways in which chemotherapy medication can be given, including tablets and injections directly into a vein.

The team caring for you will help come up with a treatment plan for your specific circumstances.

Read more about how chemotherapy is carried out and who can use chemotherapy.

Side effects

Chemotherapy is a very effective cancer treatment that has helped save millions of lives, but it does cause side effects.

The medicines used in chemotherapy can't distinguish between fast-growing cancer cells and other types of fast-growing cells, such as blood cells, skin cells and the cells inside the stomach.

This means that most chemotherapy medications have a poisonous effect on the body's cells, causing problems including:

  • feeling tired and weak all the time
  • feeling and being sick 
  • hair loss 

Some people only have minimal side effects, but for most people, a course of chemotherapy can be unpleasant and upsetting.

Living with and adapting to the side effects of chemotherapy can be challenging. However, it's important to realise that most, if not all, side effects will disappear once the treatment is complete.

There is no risk of the side effects of chemotherapy being passed to other people, including children and pregnant women, if they are in close contact with someone having chemotherapy.

Read more about the possible side effects of chemotherapy.

Targeted therapies

In the past, any medication used to treat cancer was regarded as chemotherapy. However, over the last 20 years, new types of medication that work in a different way to chemotherapy have been introduced.

These new types of medication are known as targeted therapies. This is because they're designed to target and disrupt one or more of the biological processes that cancerous cells use to grow and reproduce.

In contrast, chemotherapy medications are designed to have a poisonous effect on cancerous cells.

Page last reviewed: 20/02/2015

Next review due: 20/02/2017