Immunotherapy is a type of cancer treatment that takes a person’s own immune system to fight against cancer. The treatment method has the ability to stimulate or alter how the immune system works naturally. It looks for the cancer cells and attack them. Immunotherapy has been considered as a promising cancer treatment. It is designed to boost the production of cells that fight against cancer in the body or help the healthy cells to identify cancer cells and destroy them. In a simpler terms, immunotherapy is designed to treat the body, to make it strong enough to fight against cancer.
Immune system is composed of numerous organs, antibodies (proteins) and immune cells that function together to fight against diseases and infections that occur in our body. It keeps track of the substances exist in our body. When a new substance is detected which the immune system does not recognize, it raises an alarm causing the immune system to attack the foreign substances. For instance, germs has proteins that are foreign to immune system and by its nature, immune system automatically attacks the germs. Any substances that enter the body that are unfamiliar to the immune system such as germs or cancer cells, they will be destroyed by the immune system.
However, sometimes the immune system faces challenges in identifying cancer cells. Cancer arise when there are changes in normal, healthy cells and they grow out of control. As cancer cells develop from healthy cells that are familiar to the immune system, making it unable to recognize them as unfamiliar cells because they are not distinct enough, causing people with healthy immune system to develop cancer. In other cases, immune system does identify the cancer cells but its fight may not be strong enough to damage them. Another potential reason why immune system may not be able to defeat cancer cells is because sometimes the cancer cells could also release certain substances that prevent the immune system from finding and destroying them.
The Immune cells include:
- B-cell lymphocytes are white blood cells that produce antibodies that fight against infections.
- T-cell lymphocytes are white blood cells that target and damage cells that are diseased. These cells also signal other diseased cells or foreign cells that are present in the body.
- Dendritic cells are immune cells that engage with T-cells to boost the responsiveness of immune system.
- Granulocytes are white blood cells known as neutrophils, eosinophils and basophils, which are responsible for fighting against infections.
Recently in the medical field, there have been some advancements of treatments with immunotherapy and the investigation is still ongoing. Currently, the type of cancers that can be treated with immunotherapy are:
- Lung cancer
- Kidney cancer
- Liver cancer
- Bladder cancer
- Brain cancer (brain tumor)
- Breast cancer
- Cervical cancer and ovarian cancer
- Colorectal cancer
- Head and neck cancer
- Prostate cancer
Immunotherapy is given via drugs or cell-based therapy. This is done by extracting and modifying a patient’s immune cells then infuse it back to the body. This will restore and improve how the immune system will find and attack the cancer cells. Followings are the types of Immunotherapy used to treat cancer in the present days:
- Adoptive cell therapy is done by removing and changing the immune cells, construct new proteins and return them back into the body. The modified cells will look for cancer cells and damage them. Chimeric antigen receptors (CAR) is used to modify T-cell that fight against cancers.
- Cancer vaccines works by stimulating the responsiveness of the immune system that protects the body against diseases. The substances are modified and infuse back to the body for the immune system to fight cancers.
- Immunomodulators are substances that alter the biologic response of the body. They boost the ability of the immune system to find and destroy cancer cells. Treatments include checkpoint inhibitors which releases natural brake on the immune system so T cells recognized the cancer and attack the tumors.
- Monoclonal antibodies designed to destroy particular parts of cancer cells. It can also be used to deliver drugs, toxins, or radioactive material directly into the tumors.
- Oncolytic viruses are modified in the laboratory before it is given to the patient. The viruses will infect and kill the cancer cells.
Immunotherapy is given through intravenous infusion. It could be given on daily, weekly or monthly basis depending on the stage and type of cancer the patient has. If immunotherapy is performed in a cycle, there shall be a rest period after the treatment. This will give the body some to time to produce healthy cells. The type of immunotherapy and how the body response to the treatment will determine the duration of the treatment.
To determine if immunotherapy is an accurate treatment option for the patient, consulting the doctor about the symptoms and potential health risks of each individual is an essential part of the treatment plan. As researchers are constantly discovering more data about immunotherapy and other cancer treatments, recommendations may change.