By Yvonne Fong
Cancer is a disease caused by a mutation in the cell's genes that control how the cell grows and divides. These mutations may cause the cell to divide rapidly or to fail to terminate itself after dividing so many times. Without receiving proper medical treatment the cancer could cause a multitude of complications that ultimately lead to death.
Currently the most common cancer treatments involve either Chemotherapy or surgery to remove the cancerous tumor. While these treatments are typically effective they both have their downsides. Surgery leaves you at risk for infections and damage to other organs depending on how invasive the surgery is. Chemotherapy is infamous for a multitude of unfortunate side effects such as: harming your healthy cells, weakening your immune system, loss of hair, as well as loss of appetite. These flaws in current day treatments have inspired scientists to look into genetic treatments for cancer. Afterall, if they could discover a more effective treatment to cancer without all these side effects, it would offer an alternative treatment option that doesn’t contain such harsh side effects.
A newer cancer treatment that uses genetic modifications to help treat cancer is Chimeric Antigen Receptor (Car) T-Cell Therapy. This immunotherapy treatment involves genetically modifying a patient's own T-cells to seek out and eliminate cancer cells within the body. First a patient's T-cells are collected through a process called apheresis; during this process blood is drawn from the body and a component of the blood is removed, in this case T-cells are removed. When a sufficient amount of T-cells are collected the blood that was drawn out is returned into the body. These T-cells are then sent to a lab to be genetically modified to produce Chimeric Antigen Receptors on the surface of the T-Cells. After that, the T-Cells are reproduced in a laboratory until there's enough to infuse back into the patient. Once in the body the Chimeric Antigen Receptors will recognize specific antigens or proteins on the surface of the cancerous cells and bind to them and eradicate them. This treatment would be individualized for each patient as they would genetically modify the T-Cells to specifically target the patients cancer.
So far, there have been 6 FDA approved Car T-Cell Therapies that treat Leukemia, Lymphoma, and Myeloma. For Leukemia and Lymphoma there has been evidence showing the promise Car T-Cell Therapy has in the future of treating cancer. A Study from China showed that 99% of the patients in phase II with persistent or returning B-Cell Acute Lymphoblastic Leukemia (ALL) had a complete remission after being treated with Car T-Cell Therapy with only 22% of those patients seeing the ALL return after 12 months.
Sadly, Chimeric Antigen Receptor T-Cell Therapy does have its limitations. For instance, it currently cannot be used to treat cancers with solid tumors since those in types of cancers, the antigens on the cancer cells are also on healthy cells. The reason why Car T-Cell therapy worked so well with Leukemias and Lymphomas is the fact that it targets a known antigen on Leukemia and Lymphoma Cancer cells, CD19. However, one study run by a group of scientists from Stanford, led by Dr. Majzner shows promise for treating brain cancer. When experimenting with Car T-Cells that target B7-H3, an antigen found at high levels in many cancers, it was found the treatment could shrink the size of cancerous tumors in mice's brains with little to no harm done to healthy cells.
Despite all the potential Car T-Cell Therapy contains, it doesn’t mean this treatment is truly harmless. One unique severe side effect of this treatment is cytokine release syndrome (CRS). To help stimulate and direct an immune response, T-cells will release a chemical messenger called cytokine. High levels of cytokine can result in high fevers and dangerous drops in blood pressure. These side effects can be fatal and the side effects can be more severe if the patient has extensive amounts of cancer in their body. There are also neurological effects to the Car T-Cell treatment such as triggering seizure-like activities, impairing speech, and causing intense confusion. While the side effects can be managed by drugs and steroids, these side effects cause harm to the patient, just like any other cancer treatment.
It’s evident that Chimeric Antigen Receptor T-Cell Therapy still has a long way to go before it can be the future of Cancer treatment. However for now it still provides a fresh new option for patients suffering from Leukemia, Lymphoma, and Myeloma to consider using to treat their cancers. Perhaps one day after much more research, Car T-Cell Therapy will be a viable alternative to many common Cancer treatments used today.
References:
National Cancer Institute. (2021, October 11). What Is Cancer? National Cancer Institute; Cancer.gov. https://www.cancer.gov/about-cancer/understanding/what-is-cancer
Risks of Cancer Surgery | American Cancer Society. (n.d.). Www.cancer.org. Retrieved June 8, 2023, from https://www.cancer.org/cancer/managing-cancer/treatment-types/surgery/risks-of-cancer-surgery.html
Cancer Council Victoria. (2018). Side effects of chemotherapy | Cancer Council Victoria. Cancervic.org.au. https://www.cancervic.org.au/cancer-information/treatments/treatments-types/chemotherapy/side_effects_of_chemotherapy.html
Leukemia & Lymphoma Society. (n.d.). Chimeric Antigen Receptor (CAR) T-Cell Therapy | Leukemia and Lymphoma Society. Www.lls.org. https://www.lls.org/treatment/types-treatment/immunotherapy/chimeric-antigen-receptor-car-t-cell-therapy
National Cancer Institute. (2022, March 10). CAR T Cells: Engineering Immune Cells to Treat Cancer. National Cancer Institute; Cancer.gov. https://www.cancer.gov/about-cancer/treatment/research/car-t-cells
Study Shows CAR T-Cell Therapy Is Effective at Putting Childhood Leukemia Into Remission. (2022, December 12). Cancer.net. https://www.cancer.net/blog/2022-12/study-shows-car-t-cell-therapy-effective-putting-childhood-leukemia-remission
CAR T-Cell Study Suggests Promise for Childhood Cancers - National Cancer Institute. (2019, February 14). Www.cancer.gov. https://www.cancer.gov/news-events/cancer-currents-blog/2019/car-t-cell-childhood-cancers
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