What do you mean by immune system
The lymph glands, spleen, and white blood cells comprise the immune system. It safeguards the body against infection, illness, and disease, including cancer. However, cancer can develop when the immune system recognizes cancer cells but cannot destroy them or when the cancer cells conceal themselves from the immune system.
Immunotherapy
Immunotherapy is a type of cancer treatment that uses substances made from living organisms to help our immune system fight cancer. Our immune system is important because it helps fight infections and diseases. It's made up of white blood cells, organs, and tissues of the lymphatic system. It's a form of biological therapy, which means using things from nature to treat cancer.
Conventional cancer treatment is associated with a high rate of adverse events, as it does not distinguish cancer cells from healthy cells. Immunotherapy, for example, has overcome this obstacle by training the patient's natural immune system to recognize and selectively kill cancer cells, resulting in a reduced number of manageable general side effects.
Your physician may prescribe immunotherapy alone or in combination with other cancer treatments, depending on the factors listed below for each patient:
- The type of cancer you've been diagnosed with (additional blood tests may be required)
- The stage at which your cancer has progressed
- Whether or not you have previously received specific treatments.
- Immunotherapy may be offered to you as part of a clinical trial.
How does immunotherapy work against cancer?:
The role of immune system is to detect and kill abnormal cells and also aid in preventing or terminating the growth of many cancers. Immune cells can be present in and around the tumour. These cells are known as tumour-infiltrating lymphocytes or TILs, and they are an indication of the response to the tumour cells. The people whose tumour contains TILs often recover faster than people whose tumours doesn’t contain it.
Although immune system has the ability to avoid or reduce growth of cancer, cancer cells have an alternative way to protect itself from immune system, like:
- Changes in their genetic composition which makes them less noticeable to the immune system.
- Presence of surface proteins that shunt off immune cells
- Changes in the normal cells surrounding the tumour which results
- Immunotherapy assists immune system to fight cancer in an effective way.
What are the types of Immunotherapies?
Cancer can be treated by various types of immunotherapies, such as:
- Immune checkpoint inhibitors: Immune checkpoint inhibitors are a type of cancer treatment that helps the immune system fight cancer by removing a "brake" that cancer cells can use to hide from the immune system. This allows the immune system to recognize and attack cancer cells more effectively. It's like taking the foot off the brake pedal, allowing the immune system to go full throttle in fighting cancer.
- T-Cell transfer therapy: To naturally boost the ability of T-cells to fight cancer, T-cell transfer therapy is used. This treatment uses your own immune cells that are taken from your tumour. The active cells that are good at fighting your cancer are identified or modified in a lab. Then, they are grown in large numbers and put back into your body through a vein with a needle. It's like growing an army of immune cells to fight the cancer from the inside. It is also known by various names such as Adoptive cell therapy, adoptive immunotherapy or immune cell therapy.
- Monoclonal antibodies: This immunotherapy uses lab-made proteins called monoclonal antibodies, which are designed to attach to specific sites on cancer cells. Some monoclonal antibodies can spot cancer cells so that they become easily identifiable by the immune system and hence can be destroyed. It's like putting a spotlight on cancer cells to make them stand out and easier to target for the immune system.
- Treatment vaccines: Treatment vaccines are a type of immunotherapy that uses a patient's own immune system to fight cancer. Unlike preventive vaccines that prevent illness, treatment vaccines are used after someone already has cancer. They work by training the immune system to recognize and attack cancer cells. Essentially, it's like giving the immune system a "wanted poster" of the cancer cells, so it knows what to look for and can destroy them.
- Immune System modulators: Substances that boost the immune system response against cancer are called as immune system modulators. Few agents act by affecting particular parts of the immune system while others act in generalized way. They work by changing the way the immune system behaves, making it more active and better able to target cancer cells. It's like giving the immune system a pep talk and telling it to work harder to fight off the cancer.
Which cancers are treated with immunotherapy?
There are various types of cancers that can be treated by immunotherapy drugs. However, in comparison with surgery, chemotherapy or radiation therapy, immunotherapy is not used as widely as these techniques. It is often used when other types of treatments, like chemotherapy or radiation, have not worked or have stopped working. Essentially, immunotherapy can be a powerful tool in the fight against cancer, no matter what type it is.
Immunotherapies have been approved and are currently being used to treat a variety of cancers worldwide, including the following:
- Cancer of the lungs
- Renal cell carcinoma/kidney cancer
- Cancer of the skin
- Breast cancer
- Colon cancer
- Stomach cancer
- Testicular cancer
- Hepatocellular carcinoma
- Cancer of the mouth
There are numerous other cancers for which immunotherapy research is ongoing.
How is immunotherapy given?
Immunotherapy can be administered in different ways. These are:
- Intravenous (IV): When the immunotherapy is directly administered into a vein.
- Oral: When immunotherapy is given in the form of pills or capsules that are required to be swallowed.
- Topical: When the formulation of immunotherapy is in the form of cream that you rub onto your skin. It can be used for very early skin cancer.
- Intravesical: When the immunotherapy is directly administered into the bladder.
What are the side effects of immunotherapy?
Immunotherapy may result into unwanted effects, including fatigue, nausea, diarrhea, and skin rashes, many of which happen when body’s immune system, which has been boosted to fight cancer start acting on healthy cells and tissues inadvertently.
In some cases, it can also cause more serious side effects, such as inflammation in the lungs, liver, or other organs. However, it's important to remember that not everyone experiences side effects and many people tolerate immunotherapy very well. If you are considering immunotherapy, your doctor can help you understand the potential side effects and how to manage them.