Immunotherapy uses our immune system to fight cancer. It works by helping the immune system recognise and attack cancer cells.
You might have immunotherapy on its own or with other cancer treatments. Immunotherapy is a standard treatment for some types of cancer. It is in trials for other types of cancer.
There are different types of immunotherapy. These include monoclonal antibodies, checkpoint inhibitors, and vaccines. Some types of immunotherapy are also called targeted treatments or biological therapies.
Our immune system works to protect the body against infection, illness and disease. It can also protect us from the development of cancer.
The immune system includes the lymph glands, spleen and white blood cells. Normally, it can spot and destroy faulty cells in the body, stopping cancer developing. But a cancer might develop when:
- the immune system recognises cancer cells, but it is not strong enough to kill the cancer cells
- the cancer cells produce signals that stop the immune system from attacking it
- the cancer cells hide or escape from the immune system
Side effects of immunotherapy
Immunotherapy causes the immune system to become more active. That means it is better at finding and attacking cancer cells. However, immunotherapy can also cause unwanted effects. These are very different to the side effects of other cancer treatments, such as chemotherapy or radiotherapy.
Checkpoint inhibitors, for example, can make the immune system too active. This causes inflammation in the body. The most common parts of the body they affect are the:
- skin – causing a rash, itching or changes in skin colour
- glands in the body that make hormones – causing problems such as sweating, weight changes, feeling more hungry or thirsty, passing more urine (peeing), loss of sex drive, feeling tired (fatigue) or headaches
- bowels – causing diarrhoea or tummy pain
- joints – causing pain and swelling
More rarely, these drugs cause problems in other places, such as:
- the liver
- the lungs
- the heart
- the nerves
- the brain
- other organs
Sometimes this type of side effect can start weeks, months or even years after you finish treatment.
Some people have very few side effects, but the side effects of checkpoint inhibitors can be serious.
For further information, visit Macmillan Cancer Support.