The Promising Use of Tumor-Infiltrating Lymphocytes in Cancer Immunotherapy

It is no secret that cancer is extremely prevalent in the healthcare world today. Due to such vast detrimental impacts on people worldwide, various methods have been produced over time to combat cancer. Recently, a novel field of cancer treatment involving using one’s own immune system to battle the disease has been studied, and methods of immunotherapy to treat cancer have been developed. 

One method of immunotherapy, T-cell transfer therapy, has been proven effective in terms of long-term clinical benefits in certain cancer treatments. T-cells are a type of white blood cell, otherwise known as lymphocytes, which play a critical role in the immune system. Essentially, T-cells work by identifying foreign elements or intruders and building a customized defense against them. After identification, the T-cell then replicates to either work as a memory T-cell, which will quickly and easily identify this invader in the future, or an effector T-cell, which actively destroys the invader (T Cells: Types and Function, 2023). A couple main types of T-cell immunotherapy treatments exist and have been proven effective—TIL (tumor-infiltrating lymphocyte) therapy and CAR (chimeric antigen receptor) T-cell therapy. CAR therapy involves altering a person’s T-cells in the lab to develop particular proteins that allow T-cells to bind to specific other proteins on the surface of cancer cells, thus combating the disease (T-cell Transfer Therapy, 2024). 

TIL T-cell therapy works in a slightly different way. Instead of genetically engineering the body’s healthy, functional T-cells, TIL therapy involves a backwards-stepwise approach. In the TIL method, lymphocytes directly from cancerous tissue are used to discover T-cells that best recognize the tumor cells. Next, these T-cells are treated to generate vast quantities quickly, in hopes a high enough number of these specific T-cells will be effective in killing the tumor or overcoming immune-suppressing signals present (T-cell Transfer Therapy, 2024). Essentially, the goal is to expand the amount of TILs in a patient’s system already trained to recognize and attack a patient’s tumor. 

Currently, the FDA has only approved of a TIL T-cell therapy to treat melanoma. Although breakthroughs in advance-stage melanoma treatment have been discovered using BRAF and MEK inhibitor therapies, the 5-year survival rate of those with the disease is only 50%. However, through the use of TIL T-cell therapy in several clinical trials over the past few years, significant long-term clinical benefits were observed in phase II and III trials of advanced-stage melanoma patients (Klobuch et. al., 2024). This is just one instance showing the promising nature of TIL T-cell immunotherapy for cancer patients. Other encouraging findings of TIL therapy include cervical squamous cell carcinoma and cholangiocarcinoma (T-cell Transfer Therapy, 2024). However, further clinical studies need to be done to prove the therapeutic benefit for patients with other forms of cancer before the FDA can approve.

 TIL T-cell therapy appears to be a promising and impactful method of cancer treatment that will likely have significant implications for the future of cancer research. Although still in its infancy, such methods of cancer immunotherapy offer cancer patients and their loved ones alike hope for recovery. Overall, cancer has had detrimental impacts on the community, but TIL-cell therapy may change the tide of our society for the better, giving people a long-lasting, cancer-free life. 

Resources

Boldt, C. (2021, April 15). TIL therapy: 6 things to know. MD Anderson Cancer Center. https://www.mdanderson.org/cancerwise/what-is-tumor-infiltrating-lymphocyte-til-therapy--6-things-to-know.h00-159460056.html. 

Klobuch, S., Seijkens, T. T. P., Schumacher, T. N., & Haanen, J. B. A. G. (2024). Tumour-infiltrating lymphocyte therapy for patients with advanced-stage melanoma. Nature Reviews Clinical Oncology, 21(3), 173–184. https://doi.org/10.1038/s41571-023-00848-w. 

T-cell transfer therapy - immunotherapy. (2022, April 1). National Cancer Institute. https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/t-cell-transfer-therapy. 

T Cells: Types and Function. (2023, January 17). Cleveland Clinic. https://my.clevelandclinic.org/health/body/24630-t-cells.