.jpg)
The death toll from cancer, which currently stands at 8.2 million each year, is expected to rise with an aging population. [1] There are two broad types of carcinomas: metastatic, which usually results in cancer-related death, and nonmetastatic. Metastasis was once considered a phenomenon in the later stages of disease progression, but in recent years, metastatic dissemination has been observed during the early stages of cancer development. [1] Cancer cells that have metastasized will adapt cellular traits to allow them to invade distant organs following their getaway from primary tumors. [1]
An inflammatory response linked to cancer during various stages of tumorigenesis is responsible for genomic instability, epigenetic alteration, cancer cell proliferation, enhancement of anti-apoptotic pathways, and angiogenesis, eventually leading to the development of tumor spread. [1] In recent decades, inflammatory immune cells have been found to be an indispensable part in cancer-related inflammation. [1] Therefore, there has been a redirected focus in understanding how immune cells “impact tumor fate through different stages of disease: early tumor transformation, clinically detected tumors, metastatic dissemination, and therapeutic intervention.” [1]
Over 150 years ago, Rudolph Virchow was the first to focus on the link between the immune system and cancer. [2] It is the immune system's ability to ward off pathogens or infected/malignant cells that accounts for the relationship between cancer and immunity: “it detects "nonself" antigens from pathogens or infected/malignant cells; it encompasses effector functions that specifically target and destroy the pathogen or infected/malignant cells while protecting the host; and it develops immunological memory via the adaptive immune responses for subsequent defense mechanisms following an injury or an attack against the host.” [2] In the immune system’s defense, it has obtained the features for immunoediting, which “provides a balance between immune surveillance and cancer progression in the realm of oncology.” [2]
The defense system of biochemical processes that protect the body against “nonself” proteins consist of the immune system’s “soluble bioactive molecules, cytokines, proteins, and cells.” [2] An immune system's innate and adaptive responses are responsible for protecting the host and maintaining homeostasis. [2] These immune responses are considered innate because they are fast-acting and nonspecific, such as their response against “pathogenic microbes, allergenic antigens, or non-self-proteins or molecules.” [2]
Several cancers are immune-resistant due to the nature of their triggers that bypass the immune response. [2] Consequently, research has been focused on developing therapies that utilize the immune system as a tool for treating various forms of cancer. Cancer immunotherapies are a specific type of oncology treatment that uses the body's own innate and adaptive immunity strategies. [2] There are several different types of immunotherapies for cancer: “vaccines, monoclonal antibodies, recombinant cytokines, small molecules, and autologous T cells.” [2] The most appropriate therapy for the patient depends on the location, type, and stage of the cancer. [2]
Recent advances in cancer therapy have been impressive. New treatment options are now available due to a greater understanding of the “cellular and molecular pathways leading to tumor development, escape, and spread.” [3] In the past several years, several classes of molecularly targeted drugs have gained approval for human-use and come to market. [3] While the field has made considerable progress, one of the biggest challenges is understanding how cancer immunotherapy differs between children and adults. There has been increased research regarding the immune system's role in pediatric cancer. [2] However, the development of cancer immunotherapies for children is very behind what is available for adult cancer patients. [2] In order to choose the proper cancer immunotherapy depending on the type of cancer, the location of cancer, and differences between immune cell compositions of adults and children, it is vital to determine what differences exist between the immune cells. [2]
References:
1. Gonzalez, H., Hagerling, C., & Werb, Z. (2018, October 1). Roles of the immune system in cancer: From tumor initiation to metastatic progression. Genes & development. Retrieved March 1, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6169832/
2. Pandya, P. H., Murray, M. E., Pollok, K. E., & Renbarger, J. L. (2016). The immune system in cancer pathogenesis: Potential therapeutic approaches. Journal of immunology research. Retrieved March 1, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5220497/
3. Papaioannou, N. E., Beniata, O. V., Vitsos, P., Tsitsilonis, O., & Samara, P. (2016, April 21). Harnessing the immune system to improve cancer therapy. Annals of Translational Medicine. Retrieved March 1, 2022, from https://atm.amegroups.com/article/view/10188/html
Contributors:
Author: Rayven Hall
Editor: Sara Giarnieri
Health scientist: Rayven Hall