Cancer Immunotherapy

This information is useful for children, adults, and older adults
A man possibly undergoing immunotherapy treatment for cancer.

When your immune system identifies something harmful in your body, it makes antibodies to attack and kill it. But with cancer, the process is not so simple.  

For years, doctors have known that the immune system, which includes cells, tissues and organs, mobilizes to find and destroy cancer cells—just as it fights off bacterial or viral infections. The difference is that cancer can progress in the patient’s body. This happens, in part, because of the cancer cells’ ability to outsmart specific immune cells called regulatory T cells. Regulatory T cells (a type of white blood cell) are the body’s natural “brake” mechanisms. They prevent their fellow T cells—which kill cancer cells and other foreign invaders—from running rampant and attacking healthy cells and tissue. Cancer cells evade T cells by pretending to be normal, healthy ones. This means that they are essentially under the protection of regulatory T cells.       

So, what if there were a way to help the body’s immune system distinguish cancer cells from healthy ones so it fights off the cancer? That’s the basic idea behind immunotherapy.

In 1999, a milestone in the development of cancer immunotherapies was reached because of research finding by Yale Medicine’s Lieping Chen, MD, PhD, a professor in the Immunobiology department and co-director of the Cancer Immunology Program at Yale Cancer Center. He discovered that a molecule, now called PD-L1, could bind to a certain cell receptor, and, in some cases, prevent the body’s immune system from attacking tumors. Dr. Chen’s research was the foundation for early clinical trials that tested a class of immunotherapy drugs called checkpoint inhibitors designed to prevent that binding action. These drugs have given years of life to patients who responded to it (roughly 20 to 30 percent of late stage cancer patients overall). But checkpoint inhibitors are just one type of immunotherapy. Today, different kinds of immunotherapy have been developed and new ones are continually being tested. Immunotherapy is considered to be the future of cancer treatment.   

At Yale Medicine, our team conducts numerous clinical trials that give eligible patients access to the latest immunotherapy drugs. Our researchers and doctors work closely together at the Yale Center for Immuno-Oncology (YCIO) to quickly discover innovative treatment therapies. Yale Cancer Center is one of only 49 National Cancer Institute (NCI)-designated comprehensive centers in the country. Our doctors play a vital role in cancer research, prevention and new treatment approaches.