Immunotherapy is used to treat cancer. It assists the immune system in fighting cancer cells in the body. In addition, the immune system helps the body fight infections and other diseases. It comprises white blood cells, organs, and lymph system tissues. Immunotherapy is a biological therapy that utilises products derived from living organisms to treat cancer. The immune system comprises several organs, tissues, and cells that work together to protect the body from foreign invaders that can cause disease.
When a disease or infection-causing agent, such as bacteria, viruses, or fungi, enters the body, the immune system tries to eliminate the invaders. This self-defence system works to keep a person from falling ill. Immunotherapy uses substances made naturally or artificially in a lab to boost the immune system. It functions to:
- Stop the growth of cancer cells
- Stop the spread of cancer cells
- Killing cancer cells more efficiently
The immune cells produce cytokines, which are protein molecules. They are introduced into the body through immunotherapy to stimulate the immune system and make it simpler for the immune cells to identify and target the cancer cells.
Types of Immunotherapy
Doctors use the following types of immunotherapies to treat cancer:
- Adoptive cell therapy: Old immune cells are removed, and modified cells are introduced into the body. The modified cells target and kill the cancer cells. Some therapies are natural killer cells and tumour-infiltrating lymphocytes.
- Cancer vaccines: Vaccines that stimulate an immune response against certain diseases are injected into the body. For instance, the human papillomavirus (HPV) vaccine protects against infectious diseases that cause throat, cervical, penile, and anal cancers. Additionally, a vaccine for hepatitis B is available, which causes liver cancer.
- Immunomodulators: These substances change the body’s biological response. They stimulate the immune system’s ability to find and kill cancer cells. Treatments include checkpoint inhibitors, cytokines, interferon, and interleukins.
- Monoclonal antibodies: These lab-made proteins attack specific parts of a cancer cell that can sometimes be directly delivered to tumours through drugs, toxins, or radioactive material.
- Oncolytic viruses: These viruses are changed in the laboratory, and the modified viruses tend to infect and kill cancer cells.
Various forms of immunotherapy can be administered in different ways, such as:
- Intravenous (IV): The immunotherapy is directly injected into the vein.
- Oral: Immunotherapy is given in the form of pills or capsules that are swallowed.
- Topical: The immunotherapy is applied in a topical form of a cream that is rubbed onto the skin. This type of immunotherapy helps treat a very early form of skin cancer.
- Intravesical: The immunotherapy is administered to the bladder.
When is Immunotherapy Needed
Immunotherapy is performed for people with cancer. Some types include:
Who are the Best Candidates for Immunotherapy
Allergen immunotherapy is given for patients with IgE-mediated allergic diseases like:
- Seasonal allergic rhinitis
- Insect venom anaphylaxis
- Perennial rhinitis
- Allergic asthma
- Atopic dermatitis
Other indications include:
- Inadequate control of symptoms taking medicines, and avoiding the triggers
- A desire to decrease the morbidity from allergic rhinitis and asthma
- To reduce the risk of anaphylaxis from a future insect sting
- When the patient experiences side effects from medicines
- When avoidance is not possible.
Who Should Not Consider Immunotherapy
People who are not ideal candidates for immunotherapy are:
- Lack of adherence
- Pregnancy before the start of AIT
- Certain age groups
- Uncontrolled asthma
- Autoimmune diseases
- Sublingual immunotherapy is contraindicated in severe asthma.
Diagnosis for Immunotherapy
The doctor assesses the medical and familial histories and performs a physical examination. The following tests are advised to diagnose cancer:
- Blood and urine tests: These are done to assess kidney function, electrolyte levels, and blood cell count. A CBC (complete blood count), tumour markers, and a complete metabolic profile may help diagnose some forms of cancer.
- Mammogram: It is an X-ray of the breast. It helps screen for breast cancer. It is one of the most critical tests to diagnose breast cancer.
- Ultrasound: This technique utilises sound waves to produce images of the suspected area. It is advised to determine if the lump is a firm mass or a fluid-filled cyst.
- Biopsy: A biopsy helps confirm the diagnosis of cancer. A specialised needle is guided by an X-ray or another imaging test for the biopsy to extract a tissue core from the suspicious area. A tiny metal marker is left at the suspected location to identify the site for future imaging tests.
- Magnetic Resonance Imaging (MRI): An MRI machine uses magnetic and radio waves to create pictures of the suspected area. Before MRI, a dye is injected for contrast imaging. Unlike other imaging tests, an MRI does not use radiation to create images.
How to Prepare for Immunotherapy
Follow the instructions given by the doctor prior to the procedure. Some of them include:
- At the consultation, the doctor will share details of the procedure and answer queries. The doctor gives the post-therapy instructions to follow.
- The doctor reviews the medical history and enquires about any allergies or pre-existing medical conditions. The doctor may advise some blood tests before the procedure.
- Avoid smoking and drinking since they interfere with the procedure.
- Inform the doctor about any ongoing healthcare supplements or prescribed medications being taken.
Possible Complications After Immunotherapy
Immunotherapy carries some complications, which can be explained as follows:
Reviewed & Updated On
Reviewed by Dr. Devavrat Arya, Director, Cancer Care / Oncology, Breast Cancer, Musculoskeletal Oncology, Medical Oncology, Thoracic Oncology on 05-Apr-2023.
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