Research
What Is Immunotherapy? Understanding a Term You See in Cancer News
Immunotherapy is one of the most talked-about cancer treatments. Here's what it actually is, the main types, and what NCI says about how it works.
Please note: this page is educational only — it is not medical advice, and it does not speculate about anyone’s health beyond reliable public reporting. For questions about your own health, talk with your healthcare team.
What people see in the news
Immunotherapy shows up in headlines about "harnessing the immune system," CAR T-cell therapy, and checkpoint inhibitors. It's often described as a newer frontier in cancer treatment. Here's what the term actually means.
What it actually means
According to the National Cancer Institute, immunotherapy is a type of cancer treatment that helps your immune system fight cancer. The immune system helps the body fight infections and other diseases, and immunotherapy is a type of biological therapy — treatment that uses substances made from living organisms.
NCI explains that the immune system normally detects and destroys abnormal cells and likely prevents or curbs the growth of many cancers. But cancer cells have ways to avoid destruction — for example, by having genetic changes that make them less visible, or proteins on their surface that turn off immune cells. Immunotherapy helps the immune system act more effectively against cancer.
NCI describes several types of immunotherapy:
- Immune checkpoint inhibitors, which block the "checkpoints" that normally keep immune responses from being too strong, allowing immune cells to respond more strongly to cancer.
- T-cell transfer therapy, which boosts the natural ability of a person's own T cells to fight cancer (also called adoptive cell therapy).
- Monoclonal antibodies, lab-made immune proteins designed to bind to specific targets on cancer cells.
- Treatment vaccines, which boost the immune response against cancer cells.
- Immune system modulators, which enhance the body's immune response more broadly.
NCI notes immunotherapy drugs are approved for many types of cancer, but that immunotherapy is not yet as widely used as surgery, chemotherapy, or radiation. It can also cause side effects, many of which happen when the revved-up immune system also acts against healthy cells.
What to keep in mind
- Immunotherapy is not a single drug but a family of approaches that work in different ways.
- NCI notes only a small portion of people who receive immunotherapy respond to it, and predicting who will respond is a major research area.
- Whether immunotherapy is an option depends on the specific cancer and situation.
Questions to ask a healthcare team
- Is immunotherapy an option for my type of cancer?
- Which type of immunotherapy would it be, and how does it work?
- What side effects should I watch for?
- How would we know if it's working?
Understanding immunotherapy helps make sense of some of the most hopeful — and most hyped — cancer headlines. Free, plain-language cancer education helps more people follow the science clearly.