What Is Immunotherapy, and How Does it Treat Cancer?

Immunotherapy has revolutionized cancer treatment, targeting cancer growth more effectively than other treatments and improving survival rates for certain kinds of cancers. To understand how immunotherapy works as a cancer treatment, you first need to be familiar with how the immune system works.

The immune system includes T cells that recognize foreign molecules in the body, from minor infections to more dangerous cancer cells. What makes cancer so harmful to the body is that cancer cells can act like normal, healthy cells and go undetected by the T cells. Because T cells do not recognize the cancer cells as foreign, the cancer cells can continue dividing rapidly and spread throughout the body.

Immunotherapy is an umbrella term for a variety of methods that work with the immune system to help T cells recognize and target cancer cells more effectively, according to oncologist Melissa Wilson, MD, PhD, of the NYU Langone Medical Center in New York City. Types of immunotherapy include antibodies, cytokines, vaccines, and checkpoint inhibitors. Learn more about how these types of immunotherapy treat cancer here.

While chemotherapy treats cancer by attacking rapidly dividing cells indiscriminately, immunotherapy boosts the body’s immune system to recognize and target cancer cells. With immunotherapy, healthy cells are less likely to face attack in the process.

For certain types of cancer, such as late-stage melanoma, immunotherapy can offer the best chance for a cure. Compared to other treatments for cancer, immunotherapy also offers a more durable response, meaning the cancer is less likely to return. With many types of cancer, immunotherapy treatment is helping to prolong life and increase survival rates, even if immunotherapy isn’t technically “curing” cancer.