The body’s immune system consists of a network of specialized cells that fight infection and disease. Cancer vaccines, a form of immunotherapy, are intended to stimulate the immune system to make cells that fight the cancer. This is the same principle on which the flu vaccine works, injecting pieces of the flu virus to stimulate the immune system to make cells that fight the flu virus. The cancer vaccine is made up of whole tumor cells, parts of cells, or antigens. Antigens are the substances contained by the tumor that are recognized by the immune system as foreign, inducing an immune response.

 
The cancer cells used in the vaccine are removed during surgery then killed, usually by radiation. These cells are then injected into the patient. The antigens on the tumor cell surface remain intact and can stimulate a specific immune system response. The cancer cells that carry these antigens are identified and attacked. Cancer vaccines often have other ingredients added to them, called adjuvants, which help boost the immune response in general, improving the effectiveness of the vaccine.

 
Cancer vaccines can be autologous or allogenic. Autologous vaccines are made with the patient’s own inactivated tumor cells and injected back into them. Allogenic vaccines are made with another person’s inactivated tumor cells or the combined tumor cells of several people.

Currently there are no cancer vaccines approved by the FDA for use as a standard treatment. There are many vaccines being tested for use against a variety of cancers in ongoing clinical trials, including melanoma, kidney cancer, ovarian cancer, breast cancer, colorectal cancer, lung cancer and leukemia.