June is the 7th Annual Cancer Immunotherapy Month hosted by the Cancer Research Institute. This month celebrates the promise of immunotherapy for treating and preventing cancer.
What is immunotherapy?
Immunotherapy is a type of treatment that works with the body’s immune system to fight or prevent cancer. Immunotherapies have been approved for the treatment of a variety of types of cancers. You may have also heard the term biologic therapy in discussions about immunotherapy. Biologic therapies are made from living substances so immunotherapy is considered a type of biologic therapy.1
Why the immune system?
The body’s immune system, which is made up of specialized cells, organs, and tissues, is trained to know what is normal within the body and to recognize and attack foreign invaders, such as infections. Unfortunately, the immune system often has a difficult time recognizing and attacking cancer cells, meaning that the immune system doesn’t kick into gear to fight it. When the immune system does recognize a cancer cell, the response from the immune system may not be strong enough to stop the spread of cancer.2 Immunotherapy seeks to improve the body’s ability to recognize cancer as a foreign invader and to amplify the immune system’s power to find and kill these cells.
Immunotherapy is a promising type of treatment because it has often been effective in patients who have developed resistance to other types of treatment. The immune system also has a memory, which means that it will remember invaders like cancer cells and mount a response if a cancer cell is found, even after active treatment has ended. By ensuring that the immune system is activated and aware that the cancerous cells should be targeted and killed, there is hope that immunotherapy will provide longer lasting remissions.3
What types of immunotherapies exist?
Immunotherapies exist in different forms and work in different ways. The immunotherapies available to treat a specific cancer will vary by cancer type. To better understand how immunotherapies work, we’ve highlighted a few types:
Monoclonal antibodies: Monoclonal antibodies are a type of protein that mimics the antibodies produced by the immune system and attach to specific parts of the cancer cell. These proteins mark the cells so that more immune cells are recruited to fight the cancerous cells.
Adoptive T-cell transfer: T cells, which are cells involved in an immune response, are removed from the patient’s blood or tumor and multiplied in a laboratory prior to being reinfused into the patient. The T cells can also be modified to attack specific antigens on the cancer cells or equipped with special receptors.
Immune checkpoint inhibitors: The immune system has a natural system of checks and balances that prevent the immune system from overacting. Immune checkpoint inhibitors remove the brakes from the immune system, allowing it to respond more strongly against cancer cells.
Cancer vaccines: Vaccines can be used to enhance the body’s immune system attack on cancer cells in a person who already has cancer. These vaccines differ from vaccines given to prevent cancers caused by certain viruses, such as HPV.1,2
Immunotherapy and advanced breast cancer
The first immunotherapy for breast cancer, a monoclonal antibody that targets the protein PD-L1, was recently approved for the treatment of patients with triple-negative breast cancer (TNBC) who have inoperable advanced or metastatic breast cancer who have not received prior chemotherapy treatment for metastatic disease. PD-L1 is a protein on the cell surface that prevents the immune system from attacking. By inhibiting these proteins, the immune system can attack breast cancer cells. Other types of immunotherapies are currently being studied for the treatment of breast cancer.4
Immunotherapy to Treat Cancer. National Cancer Institute. Available at https://www.cancer.gov/about-cancer/treatment/types/immunotherapy. Accessed 05/14/19.
What Is Cancer Immunotherapy? American Cancer Society. Available at https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/immunotherapy/what-is-immunotherapy.html. Accessed 05/14/19.
Benefits of Cancer Immunotherapy. Cancer Research Institute. Available at https://www.cancerresearch.org/immunotherapy/why-immunotherapy. Accessed 5/14/19.
Immunotherapy for Breast Cancer. American Cancer Society. Available at https://www.cancer.org/cancer/breast-cancer/treatment/immunotherapy.html. Accessed 5/14/19.