The Nation's Investment in Cancer Research

Following Important Leads

Cancer Vaccines and Immunotherapy

Many deadly infectious diseases that were capable of killing millions of people have been tamed because of vaccines, which stimulate the immune system to recognize and attack pathogens before they cause disease. In the future, this approach may also be effective in preventing and fighting cancer.

A major step toward this goal came when the FDA approved a vaccine for the prevention of human papillomavirus (HPV) infection. NCI investigators throughout the Institute were involved in the discovery that HPV is a major cause of cervical cancer. Among these were Douglas Lowy, M.D., and John Schiller, Ph.D., of the Center for Cancer Research, who were instrumental in the discovery of the virus-like particle technology that led to the vaccine’s development.

HPV vaccines represent one type of cancer vaccine, which may prevent cancer before it occurs, while others, termed therapeutic cancer vaccines, may help turn a patient’s immune system against already-existing cancer cells.

Using a mouse model, Jay Berzofsky, M.D., Ph.D., of the Center for Cancer Research’s Vaccine Branch, developed a vaccine containing proteins from breast cancer cells that is capable of inducing immune responses strong enough to kill large breast cancer tumors and tumors that have metastasized to the lungs. These results show the potential for a vaccine that can stimulate the production of antibodies directed against a cell surface receptor such as HER2, which is found on breast cancer tumors.

Vaccines may be most effective as adjuvant therapy following surgery to remove the bulk of the cancer. They can be administered in conjunction with other standard treatments, such as chemotherapy or radiation, and given with cytokines to enhance the immune response.

More than a dozen vaccines are in or nearing phase III trials to refine their use, including dosing, booster schedules, and the site of vaccine administration. But for now, the FDA has not approved any therapeutic cancer vaccines.

In another example, Steven A. Rosenberg, M.D., Ph.D., NCI’s chief of surgery, has been successfully using altered versions of a patient’s own white blood cells to recognize and attack the cells of advanced melanoma. The ability to genetically engineer human white blood cells to fight against cancer, called Adoptive Cell Therapy, has opened possibilities for many other types of cancer. Dr. Rosenberg and his colleagues are currently researching use of Adoptive Cell Therapy in metastatic melanoma and renal cell cancer, among others.

“The beauty of using the immune system to fight cancer is its exquisite specificity,” says Dr. Berzofsky. “Radiation kills everything in its path. Chemotherapy kills many cells besides cancer cells. The immune system — if you could take full advantage of it — can be so specific that it can kill one cell and not all the other cells around it. You could potentially eliminate cancer cells without having the side effects of other therapies.”