For more than twenty years, researchers and doctors have been feverishly working at developing anti-cancer vaccines that use the body's own defenses to fight the disease. Soon patients can expect cancer treatments to include therapeutic vaccines aside from the traditional radiation and chemotherapy.

"It's an exciting time for cancer vaccine development," Dr. Larry Kwak, professor and chairman of lymphoma and myeloma at the University of Texas M.D. Anderson Cancer Center in Houston told Fox News.

"What's especially impressive is the diversity of cancer vaccine. It bodes well for what you're going to be seeing in the future."

More than 250 clinical trials of vaccine are underway, according to the National Cancer Institute. If any of those trials succeed it could revolutionize the medical treatment for cancer. It could mean the end of chemotherapy and radiation both of which have terrible side effects for the patient.

Cancer vaccines work by stimulating the patient's own immune system to attack cancer cells. Researchers inject antigens on the surface of cancer cells. The vaccine spurs the T cells to attack the tumors with the attached antigens. Vaccines could wipe out tumors and prevent tumors from forming without the side effects of radiation or chemotherapy. Best of all such a treatment won't weaken the immune system. And unlike radiation or chemotherapy, the cancer cells won't develop immunity from the therapy.

Cancer vaccines don't stop with existing tumors. Cancer cells can often escape from chemotherapy to spread again. Vaccines can destroy existing cancer cells. The vaccine leaves patients with T cells that can battle tumor cells years after vaccination. T cells remain locked on target for years. Once the immune system has identified the threat, it keeps reserve T cells that are ready to attack cancer cells should they return. In theory, once a patient is injected with a cancer vaccine it should make them immune from that type of cancer forever.

Some therapeutic vaccines are already ready to be tested. A vaccine called Provenge that guards against prostate cancer has been effective in extending the lives of advanced prostate patients for an average of 4.1 months. Provenge, made by Dendreon Corp. of Seattle was approved by the U.S. Food and Drug Administration in April 2010. The vaccine has a substantial price tag, for three treatments of Provenge the patient has to cough up $93,000. Despite the steep costs, cancer vaccines are still a better alternative to chemotherapy and radiation treatments.

There are more cancer vaccines in development which include treatments for breast, prostate, lung, kidney, colon, cervical, brain, and pancreatic cancers. There's even research going on in a super-vaccine that could wipe seven out ten lethal cancers. Researchers from the Mayo Clinic in the U.S. said the new vaccine activated all three components of the immune system and reduced tumor size by 80 percent. A human trial is expected in two years and if it succeeds the vaccine could be available to cancer patients by 2020.