There are treatments that use the body's own natural defenses to fight cancer. Immunotherapy, also known as biotherapy or biological response modifiers, works on white blood cells - the body's first line of defense against disease. White blood cells can be stimulated in various ways to boost the body's immune response to cancer, with little or no effect on healthy tissue. Immunotherapy can also be used to lessen the side effects of other cancer treatments.
Some immunotherapies have received approval from the Food and Drug Administration for certain types of cancer. Others are being tested in clinical trials. Biological response modifiers are developed in a laboratory and then injected into the body.
Side effects of immunotherapies can vary, but most exhibit similar symptoms, including fatigue, a rash or swelling at the injection site, and flu-like symptoms including nausea, diarrhea and fever.
There are five general types of biological response modifiers. They can be used alone or in combination with each other, or they can be used in addition to other cancer treatments.
Interferons are a group of three proteins released by white blood cells in reaction to invading organisms, to improve the immune system's reaction to cancer. Interferon alpha is approved for treatment of some cancers, including melanoma and chronic myeloid leukemia, but is being studied for use on other cancers.
Interleukins are proteins that increase growth and activity in the body's immune cells. Ten interleukins have been identified so far, but IL-2 is approved as an anti-cancer treatment, particularly for kidney cancers and melanomas that have metastasized (spread) to other regions of the body.
Monoclonal antibodies are created in the laboratory by fusing two different types of cells together. Monoclonal antibodies are designed to attack specific areas on the surface of cells known as antigens. Antigens help the body identify cells that are foreign, like germs or cancer cells, and stimulate an immune response. Monoclonal antibodies show promise both as a cancer treatment and a diagnostic tool.
Vaccines help the body recognize cancer cells and trigger the immune system to destroy them. There are several types of cancer vaccines. Some contain cancer cells that have been killed with radiation so they cannot produce new tumors. Others contain lab-produced antigens designed to attach themselves to cancer cells. Cancer vaccines are used to either help the body reject cancer tumors or to keep them from recurring.
Colony Stimulating Factors (CSF) work in the bone marrow, where red and white blood cells and platelets are produced. Colony Stimulating Factors increase the division of bone marrow cells, which strengthens the immune system and allows patients to endure higher doses of chemotherapy drugs.