Move over chemo, now harness the immune system to fight cancer
Aug 10, 2016
What is Immunotherapy
Immunotherapy, also called biologic therapy, is a type of cancer treatment designed to boost the body's natural defenses to fight the cancer. It uses substances either made by the body or in a laboratory to improve or restore immune system function. Immunotherapy may work in the following ways:
- Stopping or slowing the growth of cancer cells
- Stopping cancer from spreading to other parts of the body
- Helping the immune system work better at destroying cancer cells
How it different from chemotherapy
Rather than attacking the cancer directly, as chemo does, immunotherapy tries to rally the patient’s own immune system to fight the disease.
What the immune system does
- Immune system is a collection of organs, special cells, and substances that help protect you from infections and some other diseases. Immune cells and the substances they make travel through your body to protect it from germs that cause infections. They also help protect you from cancer in some ways.
- The immune system keeps track of all of the substances normally found in the body. Any new substance that the immune system doesn’t recognize raises an alarm, causing the immune system to attack it. For example, germs contain substances such as certain proteins that are not normally found in the human body. The immune system sees these as “foreign” and attacks them. The immune response can destroy anything containing the foreign substance, such as germs or cancer cells.
- The immune system has a tougher time targeting cancer cells, though. This is because cancer starts when cells become altered and start to grow out of control. The immune system doesn’t always recognize cancer cells as foreign.
- Clearly there are limits on the immune system’s ability to fight cancer on its own, because many people with healthy immune systems still develop cancer. Sometimes the immune system doesn’t see the cancer cells as foreign because the cells aren’t different enough from normal cells. Sometimes the immune system recognizes the cancer cells, but the response might not be strong enough to destroy the cancer. Cancer cells themselves can also give off substances that keep the immune system in check
- To overcome this, researchers have found ways to help the immune system recognize cancer cells and strengthen its response so that it will destroy them.
How does this work
Cancer cells can bind to T-cells and “turn-off” their ability to detect and kill tumor cells. Immunotherapy drugs bind to T-cells and keep them “on” by blocking a tumor cell’s access to the T-cell.