What is cancer immunotherapy?

Immunotherapy, sometimes called biological therapy, is a type of cancer treatment. It works by using your immune system to help treat the cancer.

There are several different types of immunotherapies used in cancer treatment.

Immunotherapy is currently approved in Australia for some cancers and is being trialled for other cancers.

Talk with your doctor about whether immunotherapy could benefit you.

How does immunotherapy work?

Usually, your immune system fights germs and cells that cause disease. However, some bacteria, viruses and cancer cells find a way to stop your immune system.

Immunotherapy works by:

• improving your immune system to help attack cancer cells
• removing barriers that are preventing your immune system from finding and attacking cancer cells

How is immunotherapy given?

Depending on the type of immunotherapy, it can be given:

• orally (by swallowing a pill or liquid)
• intravenously (through a drip into a vein)
• topically (by rubbing a cream onto your skin)
• intravesically (by putting it into your bladder)

How often and how long you have immunotherapy depends on:

• the type and stage of cancer
• the type of immunotherapy and how you respond to it
• what side effects you have

When is immunotherapy used to treat cancer?

Immunotherapy can be used by itself or with other cancer treatments.

Immunotherapy may be used to treat:

• head and neck cancers
• lung cancers
• kidney cancers
• liver cancers
• bladder cancers
• melanoma and Merkel cell carcinoma (a rare type of skin cancer)
• lymphoma
• leukaemia

It's also being trialled for use in other cancers, including breast cancer.

Immunotherapy is mostly used for cancer that is already advanced when diagnosed, or that has come back and spread after treatment.

When thinking about your treatment and whether immunotherapy is right for you, your doctor will look at:

• your age
• your general health
• what type of cancer you have
• how much the cancer has grown or spread
• what kind of treatment you've had already

What are the types of cancer immunotherapy?

There are several different types of immunotherapies that can be used in the treatment of cancer.

Monoclonal antibodies (mAbs)

These either:

• attach to cancer cells and alert your immune system to destroy them
• block parts of the cancer cell to slow down its growth
• carry radiotherapy or chemotherapy therapy directly to the cancer cell to attack it

Checkpoint inhibitors

Checkpoint inhibitors are the most common type of immunotherapy used in Australia for cancer treatment.

Checkpoint inhibitors work by exposing cancer cells that have been hiding from your immune system. Your T-cells (fighter cells) can then notice and attack the cancer.

Other types of immunotherapy

• Immune stimulants — stimulate the immune system to attack the cancer.
• Adoptive cell transfer — this experimental therapy boosts the ability of your T-cells to find cancer.
• Oncolytic virus therapy — viruses are used to infect the tumour cells and cause an immune response against the infected cells.
• CAR T-cell therapy — boosts the ability of your T-cells to attack the cancer. Some of your T-cells are removed from your blood. They are modified so they can better recognise the cancer cells and then returned to your blood. The process may take several weeks.

Cancer vaccines

Cancer vaccines help your body discover cancer cells. There are 2 types:

1. preventative cancer vaccines, to prevent some types of cancer caused by infections
2. treatment vaccines, to help your body fight cancer that already exists

What are the possible side effects of immunotherapy?

Common side effects include:

• eye inflammation, causing dry, irritated eyes
• joint pain
• dermatitis, causing skin rashes and itching
• tiredness
• weight loss or weight gain
• diarrhoea, abdominal pain and bloating

Less common side effects include:

• headache and changes in eyesight
• coughing
• shortness of breath
• fainting
• chest pain
• liver inflammation
• kidney problems
• excessive thirst or urination (weeing)
• muscle pain
• confusion
• seizures

Side effects can appear during or after treatment. Sometimes side effects start months or even years after immunotherapy treatment.

Make sure to tell your doctor about any new symptoms or side effects that you notice during or after your treatment. Also let them know about any side effects that are getting worse.

Your doctor will recommend treatment for the side effects. While there is a risk of severe side effects, most people have only mild side effects.

Resources and support

The Cancer Council has information on cancer and support services. You can call the Cancer Council on 13 11 20.

The Peter MacCallum Cancer Centre has videos on what to expect from immunotherapy.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.