Immunotherapy helps the immune system recognise, target or control cancer. It has changed treatment for some cancers, but it does not work for every person or tumour and can cause serious side effects.
Why cancer can evade immunity
Tumours may hide their signals, suppress immune cells or use biological “checkpoints” that normally prevent excessive immune reactions. Immunotherapies use different strategies to overcome these barriers.
Main types
- Checkpoint inhibitors release brakes on T cells.
- T-cell therapies, including CAR T-cell approaches, modify or expand immune cells.
- Monoclonal antibodies can mark cancer cells or influence immunity.
- Treatment vaccines and immune modulators stimulate selected responses.
Who may receive it?
Suitability depends on cancer type, stage, biomarkers, previous treatment, health and regulatory approval. Some treatments are standard care; others are available only in clinical trials. No biomarker predicts response perfectly.
Immune-related side effects
Activating immunity can inflame healthy organs, including skin, bowel, liver, lungs, thyroid, kidneys, heart or nervous system. T-cell therapies can cause cytokine release syndrome or neurological effects. Reactions may begin after treatment stops.
Contact the oncology team promptly for new diarrhoea, severe rash, jaundice, persistent cough, breathlessness, unusual weakness, confusion or other concerning symptoms. Early treatment can be important.
Expectations
Some people have long-lasting responses; others do not respond or develop resistance. Immunotherapy may be combined with surgery, radiotherapy, chemotherapy or targeted treatment. Supplements marketed to “boost immunity” are not cancer immunotherapy and may interfere with care.
This article provides general educational information and does not replace advice from an oncology team.
Sources
- US National Cancer Institute: Immunotherapy to Treat Cancer
- NCI: Immune Checkpoint Inhibitors
- NCI: T-Cell Transfer Therapy
Last reviewed: 28 August 2026