Chemotherapy, often called ‘chemo’, uses medicines to destroy cancer cells. Chemotherapy is used on its own or in combination with other types of treatment. Your doctor may recommend chemotherapy to shrink a tumour before surgery, to destroy remaining cancer cells after surgery, or to improve symptoms and prolong life, where it is not possible to cure the cancer.
Many different kinds of chemotherapy medicines and treatment plans are available. The kind of medicines that you are given, and how often they are needed, will depend on the type of cancer.
Chemotherapy is usually given in multiple courses (cycles) for a set amount of time, or for as long as the treatment is effective. Having the treatment in cycles allows time for the healthy cells in your body to recover between treatments.
Types of chemotherapy
Chemotherapy can be given in different ways. These include:
- oral chemotherapy that can be taken as pills (tablets, capsules) or liquid
- intravenous (IV) chemotherapy, which involves inserting a needle into a vein, then attaching the chemotherapy medicine to the needle and letting it slowly enter the body
- using a catheter (central line) that was put in during surgery [link to Surgery]
- intramuscular chemotherapy that is injected into a large muscle, such as the thigh or upper arm
- intra-arterial chemotherapy that is injected into an artery that supplies blood to the cancer
- intraperitoneal chemotherapy that is injected into the abdomen
- intrathecal chemotherapy that is delivered directly into the spine (cerebrospinal fluid)
- subcutaneous chemotherapy that is injected just under the skin, usually in the thigh or belly.
How does chemotherapy work?
Chemotherapy works by killing cells that are rapidly dividing, such as cancer cells. As well as killing cancer cells, chemotherapy also kills normal cells that are rapidly dividing. However, unlike cancer cells, normal cells can repair the damage and can recover.
The main areas of the body that are affected by chemotherapy are the mouth, stomach and bowel (gut), skin, hair and bone marrow. Damage to these normal cells causes the side effects of chemotherapy.
Side effects of chemotherapy
Chemotherapy destroys cancer cells. However, some healthy cells are also damaged, and it is this damage that causes many of the more common side effects of chemotherapy. Side effects vary depending on the drugs used. The number and type of side effects people experience varies. Some people experience few or no side effects, while others experience many. Most are temporary and can be treated or managed.
Some side effects will occur within hours or days of starting treatment, while others may not occur for weeks, months or even years.
Some common side effects of chemotherapy that can occur in the days or weeks after treatment include:
- fatigue (tiredness)
- nausea, vomiting and loss of appetite
- pain or soreness, such as headaches, muscle pain or nerve pain
- sores in the throat or mouth
- changes to the skin, such as itching, redness, dryness and acne
- diarrhoea or constipation (often due to the antinausea medication)
- weight gain or weight loss
- hair loss (some drugs cause hair to thin or fall out but many others don’t cause any hair loss)
- changes to your libido
- changes to concentration and memory (some people refer to this as ‘chemo brain’)
- emotional changes
- blood cell disorders, which may result in anaemia, dizziness, shortness of breath and increased risk of infection
- effects on the nervous system, such as tingling, burning or muscle weakness.
Sometimes chemotherapy can cause long-term effects. Your treatment team can give you more information. Late effects that may be noticed months or years after treatment include:
- organ damage, such as damage to the heart, kidneys, liver, lungs or brain
- increased risk of other cancers.
If you feel unwell or have any unexpected side effects while you are having treatment, you should contact your doctor.