We know our body has a great capacity to heal itself. When we’re healthy, if we skin our knee or get a nasty paper cut, our body heals in a matter of days. Even when we suffer a more serious injury, our body goes to work to heal itself while our doctors work alongside it.
Today, doctors can stimulate – and even intensify – our body’s healing capacity.
Certain cells in our body have only one job to do. That’s repair and regenerate US. In our bone marrow and even our fat, for example, we have specific cells that know how to search out damaged areas in our body and then fix that damage. These cells move into an affected area, keep dividing and regenerating in that spot, making sure we have enough healthy cells to repair our injury.
Doctors using stem cell medicine can remove some of the body’s natural healing cells, multiply them in the laboratory, and then inject them back into us to reinforce our already-working (but maybe overwhelmed) stem cells. In such cases, doctors power up our body’s natural capacity to heal.
Immunotherapy is biological treatment that works to:
-Remove the cancer cells’ camouflage so the immune system can discover them, and
-Enhance and reinforce the immune system so it can more effectively attack the cancer cells.
In the end, immunotherapy may:
-Stop cancer cell growth;
-Slow cancer cell growth;
-Stop cells from spreading to other areas of the body;
-Boost the immune system so it can kill more cancer cells. The challenge in overcoming cancer is that every patient’s cancer requires a precision combination of therapies.
Cancer immunotherapy is a great example of how stem cell medicine can work. Cancer cells are tricky, and they are especially equipped to conduct a fierce battle within our bodies. In fact, they can successfully knock down our body’s defenses.
-Sometimes, cancer cells camouflage themselves so our immune system doesn’t even recognize that they are cancer cells;
-Cancer cells can release substances that interfere with our immune system’s ability to find, isolate, surround, and kill them; and
-Cancer cells can prove to be very resilient, so even when they are discovered and interrupted by our immune system, they prove to be strong survivors.
In order to design the combination of therapies that will work best for a patient, doctors start with genetic tests. They seek to understand the patient’s immune system as well as the biology of the tumor.
Doctors have several options in their cancer-fighting arsenal.
The body has a tremendous security alert system. Its immune cells are always on patrol, searching for any sign of infection or disease. The immune cell links up with and probes proteins in a cell to detect whether that cell’s healthy and normal. If the cell is cleared, the immune cell passes on by. If the protein scan indicates the cell may be infected or damaged, the immune cell launches an attack. Once the immune system is alerted and attacks, it also unleashes specific molecules (which doctors call immune checkpoints) that shield normal cells. Some tumors emit a signal that inactivates immune checkpoints. The immune cell catalogs the tumor as a normal body part. If doctors learn enough about the tumor’s biology, they know the tumor is emitting such a signal, and they can work to stop that signal. Tumors also sometimes trick the immune system into putting brakes on its tumor attack. When doctors learn a guilty tumor is doing this, they can work with the body to release the brakes, putting the immune system’s tumor attack back in motion. The U.S. Food and Drug Administration evaluates and approves checkpoint inhibitors. While there’s still a lot to learn, this is a promising cancer-fighting frontier.
While we usually think of vaccines as a way to prevent a communicable disease, such as measles, a personalized, therapeutic cancer vaccine works by alerting the body’s immune system that it needs to step up its attack on a specific tumor. Right now, the only vaccine approved by the U.S. Food and Drug Administration is used to treat advanced prostate cancer. In this vaccine, stem cells are removed from the patient’s blood. In the laboratory, they are turned into immune cells and then exposed to a protein that can trigger an immune response against prostate cancer cells. Healthcare professionals use an IV to put treated cells back into the patient. The vaccine doesn’t cure prostate cancer, it instead prompts the immune system to step up its fight.
CAR T-Cell therapy (chimeric antigen receptor T-cell therapy) allows doctors to reprogram cells to fight cancer. Healthcare professionals take some blood from you and sort out some of your T cells. These T cells help your body fight cancer. In a medical laboratory, healthcare professionals then add chimeric antigen receptors, which are bioengineered to help T cells locate and attack your specific type of cancer. Once the modified cells are returned to your body, the CAR T cells multiply like crazy. They zoom in on cancer cells and destroy them.
Researchers are exploring how to reprogram T cells so they can better locate cancer cells. To date, research is being conducted in synovial sarcoma (a soft-tissue cancer) and metastatic melanoma.
Tumor-infiltrating lymphocytes (TILs) are white blood cells that fight cancer. They often are found in large numbers in extracted tumors. As a result, inquisitive researchers are now removing some of these cells and then growing them in a medical laboratory. Once they have a targeted number of these cells, the researchers add special proteins called cytokines. The belief is that cytokines should help TILs find and kill cancer cells more efficiently. The hope is that the large number of these treated white blood cells, equipped with the equivalent of cancer-vision-goggles, will overwhelm the cancer. Colorectal, ovarian, kidney, and skin cancer clinical trials are currently underway.
Natural Killer (NK) cells can rapidly detect and kill tumor cells. In the past, researchers had difficulty making enough viable NK cells in a laboratory. Today, improved methods that optimize laboratory production and enhance NK cells’ tumor attacking capacity are being developed. Researchers now believe genetically modified NK cells can be as effective as therapeutic T cells and may even result in less risk of graft versus host disease in the future. That is exciting news for patients who may benefit from cancer immunotherapy.
These are just some of the ways researchers and physician-scientists are unleashing our body’s ability to heal from within:
This video discusses what CAR T-cell therapy is, who it may be for, and the risk and benefits of the treatment in cancer patients.
The concept of ‘teaching’ the immune system to recognize and destroy cancer cells is over a century old, but the development of immunotherapeutic strategies for cancer was slow for many decades.
Immunotherapy has the potential to achieve long-lasting remissions, even cures, for cancer.