Immunotherapy

Cancer immunotherapy, also known as immuno-oncology, is a form of cancer treatment. It uses substances to boost or change your body’s own immune system so that it can find and attack cancer cells and prevent, control, and eliminate cancer. Many types of immunotherapies are increasingly being used to help extend the lives of many cancer patients. Immunotherapy for cancer is available in a variety of forms. These include targeted antibodies, cancer vaccines, adoptive cell transfer, tumour-infecting viruses, checkpoint inhibitors, cytokines, and adjuvants. They are a form of biotherapy, or biologic therapy, as they use materials from living organisms to fight disease.

The normal function of your immune system is to help protect you from infections and diseases. It does this by detecting and destroying abnormal or foreign cells.

Your immune system finds it harder to target cancer cells. Cancer starts when normal, healthy cells change and start to grow out of control. The cancer cells may not be different enough from normal cells for your immune system to see the cancer cells as foreign cells. Also, cancer cells can be less visible as they produce signals that stop your immune system from attacking them or the cancer cells hide or escape from your immune system. Sometimes your immune system recognises cancer cells but its response is not strong enough to destroy the cancer.

Immunotherapy helps your immune system to recognise cancer cells and strengthens its response to destroy them. It works by:

• educating your immune system to recognise and attack cancer cells
• boosting your immune cells to help remove cancer
• providing your body with additional components to enhance your immune response.

Your immune system has a “memory”, called immunomemory and it can remember what cancer cells look like. If cancer returns, it can target and eliminate cancer.

The administration and frequency of immunotherapy depend on your cancer, the drug used, your treatment plan, and how your body reacts to treatment.

Before immunotherapy your doctor will discuss with you how immunotherapy works, possible side effects, and how and when your immunotherapy will be given. You may be tested for biomarkers that can indicate whether cancer immunotherapy would be an effective treatment.

Immunotherapy is usually given on an outpatient basis such as in your doctor’s clinic or an outpatient unit. You may have immunotherapy treatment every day, week, or month. It may be given in cycles whereby you have a period of treatment followed by a period of rest so that your body is able to recover, respond to immunotherapy, and build new healthy cells.

Your treatment may be given intravenously (IV) which is directly into your vein, by swallowing a pill or capsule, topically using a cream that you rub onto your skin, or by intravesical therapy where the immunotherapy goes directly into your bladder.

You can expect to be closely monitored whilst having immunotherapy to check for any side effects and to ensure you are well enough for treatment before each cycle. You may also have blood tests a few days before each treatment to check how your body is coping with the treatment.

After immunotherapy treatment, you will have follow-up checks.

Immunotherapy can be accompanied by side effects. This may be due to the stimulation of your immune system also acting against healthy cells and tissues in your body. Side effects can vary depending on the specific immunotherapy used, your type of cancer and how advanced it is, and how healthy you are before treatment. Your doctor will advise you on what to expect.

Common side effects may include:

• skin reactions – pain, swelling, soreness, redness, itchiness, or a rash
• flu-like symptoms – fever, chills, fatigue, weakness, dizziness, nausea or vomiting, muscle or joint aches, headache, cough or trouble breathing, low or high blood pressure
• swelling and weight gain from retaining fluid
• loss of appetite
• heart palpitations
• mouth sores
• diarrhoea
• sinus congestion
• infection
• organ inflammation

Typically, immunotherapy-related side effects can be managed safely if they are recognised and addressed early.

Immunotherapy is only given for a set period of time, currently over a maximum of two years. It offers the possibility of long-term control of cancer even after treatment has finished. This is because of your immune system’s memory or “immunomemory” which may result in longer-lasting and potentially permanent protection against cancer recurrence.

Immunotherapy can cure some cancers. It is effective in treating many cancers and helps to extend and save the lives of many cancer patients. But it doesn’t work for every patient and its effectiveness depends on the type of cancer and its advancement. Research in immunotherapy is ongoing to understand this further and to develop more precise, personalised, and effective cancer treatments with potentially fewer side effects.