What is Immunotherapy Cancer Treatment?
Immunotherapy, or biological therapy, is a form of cancer treatment that uses the power of the body’s own immune system to control, eliminate, and prevent cancer. In the last few decades immunotherapy has become an integral part of treating certain types of cancer. Immunotherapy cancer treatment has been approved in the US and elsewhere as the first line of treatment for several types of cancers. It can also be used along with standard treatments, or for patients whose bodies have been resistant to prior treatments.
The Role of the Immune System
To understand how immunotherapy works, you must understand how your body’s immune system works. Your body’s immune system is a group of organs, special cells, and substances that help protect you from infection and disease. It also protects you from cancer to a certain extent. Any new substance in the body that the immune system does not recognize will raise an alarm. This alarm will cause the immune system to attack anything containing foreign substance including viruses, bacteria, and even cancer. The body sometimes struggles to recognize and destroy cancer cells because they begin as normal, healthy cells. Cancer forms when normal cells change and start to grow out of control.
Cancer Occurs for the Following Reasons:
- The immune system does not see the cancer cells as foreign because the cells are not different enough from normal cells.
- The immune system recognizes the cancer cells, but the response is not strong enough to destroy cancer.
- Cancer cells give off substances that keep the immune system from finding and attacking them.
How Immunotherapy Works
Immunotherapy works in one of two ways. The first is by increasing the immune system’s natural ability to defend itself. This will aid the immune system in working smarter or harder in fighting and attacking cancer cells.
The second-way immunotherapy works are by using substances created in a lab that is identical to immune system components. These substances are used to restore the immune system or improve how your immune system works to find and attack cancer cells.
Common Types of Immunotherapy
Checkpoint inhibitors- These work by disrupting the cancer cell’s signals, which then exposes them to the immune system for an attack. Immune cells can usually differentiate healthy cells from intruders, however, at certain checkpoints the cancer cells send out a special signal to the immune cells. This signal tricks them into thinking they are normal cells. A checkpoint inhibitor will block that signal and expose the cancer cell for attack by the immune system.
Chimeric Antigen Receptors (CAR)-T-Cell therapy- This therapy involves mixing T-cells from a patients’ blood with a special virus. This virus teaches the T-cells to attach to tumors. The T-cells are then returned to the patient’s body so they can locate, attach to, and kill cancer.
Cytokines- This treatment uses cytokines, which are small proteins that carry messages between cells. The cytokines stimulate immune cells to attack cancer cells. During this treatment, cytokines are synthesized in the lab and injected in much larger doses than the body would normally produce.
Immunomodulators- Certain types of cancer are treated with this drug by boosting part of the immune system. These drugs work in many ways, including telling the immune system to turn up certain proteins and to turn down others.
Cancer Vaccines- A substance put into the body to start an immune response to certain types of cancer. This type of treatment can be given to prevent or treat certain types of cancer. Some vaccines are injections, while some are a re-infusion of the patients’ enriched blood. Research on cancer vaccines is in the early stages and is mainly only available through clinical trials.
Monoclonal Antibodies- These are the man-made version of the immune system’s proteins. They can be designed to attach to specific proteins on cancer cells. This flags the cell so that the immune system can find and destroy cancer. This treatment may also work by blocking a receptor found on cancer cells that is important to their growth.
Oncolytic Viruses- This treatment uses viruses that have been modified in a lab to infect and kill certain tumor cells. These viruses reproduce efficiently in cancer cells without harming healthy cells. When a virus infects a tumor cell, the virus makes copies of itself until the cell bursts. The dying cancer cell then releases materials that allow it to be recognized by the immune system. Some examples of the viruses being used in the study of this type of therapy include poliovirus and the herpes simplex virus.
Radioimmunotherapy- This therapy combines a monoclonal antibody and a radiation source. This delivers radiation directly to the specific tumor cells, but often in lower doses and over a longer period of time.
What Types of Cancers Does Immunotherapy Treat?
As of December 2019, the FDA has approved immunotherapy treatment for nearly 20 forms of cancer, as well as some forms of mutated cancers. Continued studies and clinical trials are currently taking place with the goal of discovering more ways to use immunotherapy to treat additional types of cancer. Immunotherapy is more effective for certain types of cancers than others. It is used alone for some of these cancers, but for other types, it works best when used along with other treatments such as chemotherapy and radiation. A cancer diagnosis can be devastating, however, thanks to the great strides being made by modern medicine, immunotherapy can help many people in their battle against it.