How Do Cancer Immunotherapies Work?

How different types of immunotherapies help the body’s immune system recognize and fight cancer.

Immunotherapies work by helping the body's immune system identify and attack cancer cells, and can be used in tandem with other cancer treatments.

Medically reviewed in November 2021

There are many different types of treatment that are used for cancer, including surgery, radiation, and chemotherapy. Another treatment option is immunotherapy, the name for drugs that use your own immune system to fight cancer. Immunotherapy can be used by itself or along with other treatments. The treatment options a cancer care team recommends will depend on a number of factors, including the kind of cancer, the stage, and a person’s overall health.

Types of immunotherapies
There are several different categories of immunotherapies, but these therapies generally work in one of two ways. Some work by boosting the immune system's natural defenses so it attacks cancer cells more effectively. Others work by providing the body with extra substances to help the immune system fight cancer.

Here’s a closer look at the types of immunotherapies that are available:

  • Adoptive cell therapy. This treatment involves removing existing immune cells from the body, and either altering those cells or increasing the number of those cells. These changes help the immune cells recognize and attack more cancer cells when reintroduced into the body. This approach can be used to treat certain types of leukemia, lymphoma, and melanoma. One example is chimeric antigen receptor (CAR) T-cell therapy. With this therapy, immune cells called T-cells are taken from the blood, mixed with a disarmed virus, and delivered back into the body via an infusion. The T cells will find, attach to, and kill the cancer.
  • Cancer vaccines. These therapeutic vaccines can target cancer cells in certain cancer types—such as prostate cancer and bladder cancer.
  • Checkpoint inhibitors. These drugs block pathways in the immune system, which can stimulate new immune responses and help eliminate cancer cells. They are currently used to treat more than a dozen types of cancer, including cervical cancer, head and neck cancer, liver cancer, bladder cancer, breast cancer, and lung cancer.
  • Cytokines. These drugs stimulate the immune cells to attack cancer using cytokines, which are proteins that carry messages between cells. They can be used for certain types of kidney cancer, blood cancers, skin cancers, and tumors that form on bones and soft tissues.
  • Monoclonal antibodies. These lab-made versions of immune system proteins are designed to attack a specific part of a cancer cell. They are used to treat many forms of cancer, including breast cancer, brain cancer, colorectal cancer, and lung cancer.
  • Oncolytic virus therapy. This form of treatment uses viruses that have been altered in a lab in order to infect and destroy cancer cells. So far, there is only one approved by the Food and Drug Administration for metastatic melanoma, but there are clinical trials underway to combine an oncolytic virus and checkpoint inhibitor for people with colorectal cancer, ovarian cancer, and appendiceal cancer.

Deciding to use immunotherapy
Cancer is a different experience for everyone, and the best approach to treating cancer depends on many different factors. Immunotherapies offer promising treatment for many people, but they are not right for every type of cancer or every person who has cancer. If you or a loved one is living with cancer, talk to your healthcare team about your treatment options. They can help you determine if immunotherapy should be included in your treatment plan.

Article sources open article sources

American Cancer Society. "How Immunotherapy Is Used to Treat Cancer."
Cancer Research Institute. "How Cellular Immunotherapies Are Changing the Outlook for Cancer Patients."
Cancer Research Institute. "Cancer Vaccines: Preventive, Therapeutic, Personalized."
Cancer Research Institute. "Immunomodulators: Checkpoint Inhibitors, Cytokines, Agonists, and Adjuvants."
National Cancer Institute. "Immune Checkpoint Inhibitors."
American Cancer Society. "CAR T-cell Therapy and Its Side Effects."
National Cancer Institute. "CAR T Cells: Engineering Patients’ Immune Cells to Treat Their Cancers."
Mayo Clinic. "Monoclonal antibody drugs for cancer: How they work."
Cancer Research Institute. "How Oncolytic Virus Therapy is Changing Cancer Treatment."
American Cancer Society. "Immunotherapy Safety."
National Cancer Institute. "Immunotherapy Side Effects."

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