Saturday, January 22, 2011

Immunotherapy and Cancer

When chemotherapy, radiation, and surgery are harsh treatments that can only kill the cancer by hurting the body, then a new type of treatment option that enhances the body's own immune system to fight off cancer would not only seem too good to be true, but almost logical in the simplicity of the concept.Although it's easier said than done, it's a concept that is being put into practice and finding some admirable success. Immunotherapy is a new treatment method which uses natural substances to encourage the body's own immune system to fight off disease, or laboratory made immune system components to fight off unwanted disease. It is primarily used for cancer patients, but also benefits patients with allergies, Crohn's disease, multiple sclerosis, and other diseases. But it is within the cancer world that immunotherapy is finding the most success and hope.According to the American Cancer Society, immunotherapy is still a small field which hasn't yet proven itself to be better than other types of cancer treatments. However, it's one that researchers say holds a lot of promise and "many future advances against cancer will probably come from this field."Immunotherapy, also called biological therapy and biotherapy, is similar to cancer vaccines which is just another form of immunotherapy. Cancer vaccines can be either therapeutic (given after a cancer is diagnosed) or prophylactic (given before a cancer can develop). Extensive research is currently being done on all types of vaccines. Initial success showing the potential of cancer vaccines is seen in Gardasil, a vaccine which can prevent cervical cancer caused by certain types of human papillomavirus infection (HPV), a sexually transmitted disease. However, Gardasil is not a true cancer vaccine since it only targets a virus that can cause cervical cancer.Immunotherapy is also similar to targeted drug therapy which seeks out those specific elements that signal cancer cells to grow. Targeted therapy drugs aim to halt specifically targeted molecules from signaling to cancer cells to begin growing and dividing uncontrollably. Some targeted therapy drugs overlap as immunotherapy drugs.When cancer develops, malignant cancer cells grow and divide uncontrollably until a tumor forms. This process happens, in part, because the body's immune system fails to recognize the cancer cells as a foreign element which it would want to attack and destroy. Immunotherapy seeks to enhance the body's own ability to identify and destroy cancer cells, and prevent their spreading throughout the body. This identification of cancer cells as foreign is enhanced in immunotherapy delivery agents to recognize those antigens or molecules that are not normal to an organ's cells, and occur only in cancer cells. Therefore, when these cancer cells give off certain molecules, it signals to the immune system that it is foreign, and must be destroyed.Immunotherapy is a complicated field involving different agents that are not called drugs or medication, but labeled as biological immune response modulators (BIRMs) or immunomodulators. These BIRMs include interferons, interleukins, colony-stimulating factors, monoclonal antibodies, cancer vaccines, gene therapy, and nonspecific immunomodulating agents. Since white blood cells are an important part of the body's immune system, many of these BIRMs are geared towards white blood cells in which there are many different types. BIRMs are also aimed at helping what are called antigen-presenting cells (APCs), which operate on the buddy system with white blood cells. APCs are the cells that tell white blood cells: "Hey, this unwanted cell I am attached to is foreign. If you see any more like it, destroy them."

There are two main types of immunotherapy agents, active and passive. Active BIRMs aim to stimulate elements of your body's own immune system to fight off the disease. Passive BIRMs are man-made immune system components which are administered with the goal of fighting off the disease without the body's immune system to help it.

BIRMs can also be classified on whether they target one specific type of antibody (unwanted cell it's seeking to prevent from aiding in the cancer process), called specific immunotherapy. Or, whether the BRM aids the entire immune system, called non-specific immunotherapy.

Currently, FDA approved immunotherapy is a part of the treatment process for many different types of cancer which include:

    * Breast Cancer
    * Cervical Cancer
    * Colorectal Cancer
    * Kidney Cancer
    * Leukemia
    * Lymphoma
    * Lung Cancer

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