Cancer is one of the leading causes of death in the United States. The three most common treatments for cancer are radiation, surgery, and chemotherapy. However, immunotherapy is a growing field and it soon may join the top three in popularity. Immunotherapy harnesses the body’s own immune system to fight the cancer cells. The immune system usually kills any type of intruder, but cancer cells can sneak through these checks. Immunotherapy helps the immune system see the cancerous cells as foreign invaders and to attack them.
Immunotherapy helps the body’s own cells fight cancer as opposed to other treatments which involve outside stimuli. The types of immunotherapy include monoclonal antibodies, immune checkpoint inhibitors, cancer vaccines, oncolytic viruses, chimeric antigen receptor T-cell therapy, and immune system modulators. Monoclonal antibodies are man-made clones of immune system proteins that can be trained to attack a specific part of a cancer cell. These cloned cells can enhance the immune system’s attack on the cancer cells. Immune checkpoint inhibitors are drugs that stop the natural brakes in the immune system, causing the response to be more powerful without any resistance.
Cancer vaccines train the body to respond to certain antigens and to attack cancer cells with those antigens. These vaccines can be made from the tumor cells themselves, from tumor-associated antigens, or from dendritic cells, which are immune cells and antigen-presenting cells. Oncolytic viruses are viruses that are trained to specifically attack and kill cancer cells while leaving normal cells alone. An example is talimogene laherparepvec (T-VEC). It is used for melanoma patients and injected directly into the tumor. After a tumor cell dies, more copies of the virus are released to infect the other cancerous cells. CAR T-cell therapy is where T-cells are removed from the body and mixed with a virus that helps the T-cells learn how to attach to tumor cells and attack them. These cells are then cultivated and grown to large numbers and injected back into the patient to attack the cancer.
Immunomodulators help boost the immune system’s response to the cancerous cells. One type is interferons, which activate certain white blood cells such as dendritic cells and natural killer cells to cause a greater response. Another type of immunomodulators are interleukins, which boost the number of white blood cells in the body in order to get a heightened attack against the cancerous cells.