Overview (What it is, why it is used and how it works)
The immune system is the body’s defence against illness and infection. Immunotherapy uses the power of the immune system to find and destroy cancer cells. This is done either by boosting the body’s own natural defences, or by creating substances in a laboratory that are similar to immune system components, to improve the immune system to locate and destroy cancer cells.
When Immunotherapy is used as a treatment
Immunotherapy can be an effective treatment option for people who have not had been successfully treated with other forms of cancer treatments such as chemotherapy and/or radiation therapy.
Types of Immunotherapies
There are a variety of immunotherapies which include:
- Immune checkpoint inhibitors: The immune system consists of various cells that protect the body from disease. One of the main types of cells that fight disease are called T cells. These cells contain checkpoint proteins which can turn an immune response on and off. While checkpoint proteins can trigger the immune system to fight a disease, other checkpoints can turn off the T cells if the T cells are active for too long or do what they should not, thereby potentially destroying healthy tissue. Certain cancers produce high levels of protein which switch off the T cells and prevent the T cells from destroying the cancer. Drugs that can turn the immune system back on are called checkpoint inhibitors and they serve to stop the cancer from switching off the T cells so that they can get to work against the cancer.
- Adoptive cell therapy: is a type of immunotherapy that targets cancer cells through mechanisms of the immune system itself. The method works by taking cells from the patient’s own blood or from the tumour, cultivating more of these cells in a laboratory and infusing the tumour-specific cells into the patient’s own cells which then find and attack the cancerous tumour cells. In some cases, the cells are modified to be able to target cancer cells more efficiently.
- Monoclonal Antibodies: are immune system proteins grown in a laboratory which use antibodies to help the immune system recognize cancer cells by ‘flagging’ them. The body normally produces antibodies which attach themselves to the surface of diseased cells to identify them to the immune system. Sometimes cancers can mask themselves from the immune system and monoclonal antibodies are used to identify them. Laboratory-produced antibodies can enhance, modify or mimic the body’s own antibodies to boost the immune system’s disease-fighting abilities.
- Oncolytic Virus Therapy: This treatment uses natural viruses that have been engineered to infect and destroy certain tumour cells without damaging the healthy cells in the body.
- Cancer Vaccines: These vaccines work differently to the traditional vaccines which are administered before a person is infected with a disease. Cancer vaccines specifically strengthen the response of the immune system to fight cancer cells.
- Immune System Modulators: These drugs boost certain portions of the immune system to treat certain types of cancer. They are generally used to treat advanced cancer and some are used to manage the side effects of other immune system modulating agents.
The length of treatment for immunotherapy varies greatly and could be daily, weekly or monthly or in a specific cycle set by the doctor.
How Immunotherapy is administered
The type of immunotherapy prescribed will determine how the treatment is administered which includes:
- Intravenously directly into a vein
- Orally in the form of tablets
- Topically in a cream that rubbed into your skin
- Into the bladder with the aid of a catheter
Side effects of Immunotherapy
A patient may experience one or more of the following side effects following immunotherapy treatment:
- Fever or chills
- Weakness or dizziness
- Dry eyes
- Weight changes
- Joint pain
- Skin rash, swelling or itching
- Diarrhoea, abdominal pain and bloating
- Low or high blood pressure
- Organ inflammation