Written by Elaine Leon | Edited by Sarah Liu
Photo by CDC
When people are told that they are diagnosed with cancer, they know it to be a semi-fatal disease with very few treatments. Some of the more well-known treatments to cancer, such as radiation and chemotherapy, are incredibly harmful to the body. Chemotherapy and radiation therapy are designed to kill cancerous cells, but they also have long-lasting side effects and kill healthy cells, which makes it harder for the body to function and protect itself from future attack[5]. Immunotherapy, on the other hand, is a specific style of treatment that teaches a patient’s compromised immune system to fight for itself by targeting cancerous cells. At its core, immunotherapy is a precision medicine approach, which means it is designed to work with the unique sequences of an individual patient’s DNA. This allows immunotherapy to be a more targeted approach to cancer, eliminating many of the harmful side effects that come with traditional radiation and chemotherapy [2].
The field of immunotherapy has been around since the late 19th century, when a German doctor noticed that his cancer patients’ tumors decreased in size when they were infected with a strain of Streptococcus, the same bacteria that cause diseases like strep throat [4]. After that, the field was not heavily explored until the 1990s, when a boom in research focusing on cancer vaccines erupted [4]. While cancer vaccines are a helpful preventative immunotherapy, another more promising immunotherapy treatment is called adoptive T cell therapy. Also known as CAR (chimeric antigen receptor) T-cell therapy, adoptive T-cell therapy is when a T-cell, commonly known as a white blood cell, is taken out of the body, altered to better attack the cancer cells, and then reinjected into the body [6].
Since cancer immunotherapy is a type of precision medicine, each person has different responses to the same treatment based on their DNA. The same vaccine can have an “almost non-existent” response rate in pancreatic cancer, a 15-30% response rate in average tumor types, and a 50-80% response rate in skin and lymph node cancer (specifically, melanomas and Hodgkins Lymphoma) [1]. While this variability may seem overwhelming, the FDA has approved and is continuing to approve a variety of immunotherapy treatments, and this field is only continuing to grow [1]. Currently, there are seven late-stage cancer vaccine treatments that are supported by Health Canada, the federal Canadian health department, alone [1], and personalized genetic tests are making it significantly easier to analyze which immunotherapy treatments work well with certain genes [3]. This further demonstrates how effective immunotherapy is as a cancer treatment, since one of the hardest parts about cancer is dealing with the harsh side effects that come with other cancer treatments.
With the arrival of a new biological age and a multitude of genetic tools, immunotherapy treatments for cancer have never been so advanced and efficient. Moreover, immunotherapy is a relatively new field that has treatments for only a few cancers, so with increased research and development, the field could expand exponentially [1]. All in all, radiation and chemotherapy have provided relief to many cancer patients, but immunotherapy offers a hopeful glimpse into the future of a more comfortable and effective way to treat cancer.
References:
[1]Esfahani, K., Roudaia, L., Buhlaiga, N., Del Rincon, S., Papneja, N., Miller, W. “A review of cancer immunotherapy: from the past, to the present, to the future.” Current Oncology 27.s2 (2020): 87-97. https://www.mdpi.com/1718-7729/27/12/87
[2]“Immunotherapy: Precision Medicine in Action.” Johns Hopkins Medicine, John Hopkins Medicine, www.hopkinsmedicine.org/inhealth/about-us/immunotherapy-precision-medicine-action-policy-brief#:~:text=It%20doesn%27t%20work%20for,are%20about%2015%20to%2020%25. Accessed 25 Jan. 2024.
[3]Kiyotani, K., Toyoshima, Y., Nakamura, Y. “Personalized immunotherapy in cancer precision medicine.” Cancer biology & medicine, vol. 18,4 955–965. 9 Aug. 2021. doi:10.20892/j.issn.2095-3941.2021.0032
[4]Koo, Si Lin, Who Whong Wang, and Han Chong Toh. “Cancer immunotherapy-the target is precisely on the cancer and also not.” Ann Acad Med Singapore 47.9 (2018): 381-387. https://annals.edu.sg/pdf/47VolNo9Sep2018/MemberOnly/V47N9p381.pdf
[5]“What’s the Difference? Chemotherapy and Immunotherapy.” City of Hope, City of Hope, 1 June 2023, www.cancercenter.com/community/blog/2022/02/whats-the-difference-chemotherapy-immunotherapy#:~:text=Both%20chemotherapy%20and%20immunotherapy%20may,as%20surgery%20or%20radiation%20therapy.
[6]Yuzhakova, D., Shirmanova, M., Sergeeva, T., Zagaynova, E., Lukyanov, K. “Immunotherapy of cancer (review). Modern Technologies in Medicine. 2016; 8 (1): 173-182. https://cyberleninka.ru/article/n/immunotherapy-of-cancer-review/viewer