Immunotherapy

Immunotherapy works differently from chemotherapy. Rather than attacking cancer cells directly, it removes the brakes the cancer has put on your immune system, or equips that system to recognise the cancer as a threat. That difference explains both its appeal and its limits: when it works it can work durably, and it does not work for everyone or every cancer.

The main kinds

Checkpoint inhibitors — PD-1, PD-L1 and CTLA-4 drugs — release the immune brakes and are the most widely used group. Monoclonal antibodies target specific markers on cancer cells. CAR T-cell therapy re-engineers a patient's own T-cells and is used in certain blood cancers. Cancer vaccines aim to train the immune response. Dendritic cell therapy collects immune cells, activates them outside the body and returns them, and is used alongside other treatments in some centres.

Who it is for

It is used in melanoma, lung, kidney and bladder cancers, in lymphoma and leukaemia, and in some others — typically in advanced or spreading disease, or where chemotherapy has stopped working. Whether it suits your cancer is decided on testing of the tumour itself, not on the diagnosis alone, so ask what marker testing has been done and what it showed before anything is agreed.

Treatment and side effects

It is given in cycles with monitoring between them. Recovery between doses is generally quicker than with chemotherapy. The side effects are different in kind: because the treatment activates the immune system, it can inflame healthy organs — skin, bowel, thyroid, liver or lungs. Most of these are manageable when caught early, which is exactly why the monitoring schedule exists and why any new symptom should be reported rather than waited out.

Before you agree to anything

Ask which specific drug is proposed, what testing supports using it in your case, how long a course is intended, and how it would be continued at home. We put those questions to the oncologist in writing before you travel. We will not tell you it is a cure or quote you a response rate: whether immunotherapy helps a particular person is genuinely uncertain in advance, and anyone promising otherwise is selling something.