Long story short: the body has its own defense system, and one of the tools it uses is the T cell. By activating those T cells in the growing tumors (which are a part of the body), the T cells can do all the grunt work and eliminate all traces of the tumor!
Stanford researchers are performing clinical trials on mice on Lymphoma, colon, breast, and melanoma cancers. Since cancers are similar in behavior across species, this vaccines is also theorized to work on others like humans as well.
Researchers Ronald Levy (left) and Idit Sagiv-Barfi (right) led the research team on the possible cancer treatment. The process involves local injection of two agents, and may be widely available because it is inexpensive. Another benefit to this breakthrough is that adverse side effects weren't observed in the trial!
This method is thorough in its elimination of cancer, since it eliminates all tumors of all sizes in the entire body. Current methods require either 1) identification and spot treatments or 2) chemotherapy + pharmaceuticals, both which are far more expensive than this proposed treatment.
One agent has already passed FDA requirements, and is clinically allowable to be used in humans. The second agent has been tested on humans, but not specifically in clinical trials. Since this is a cancer-curing agent, this second agent may not have to go through the several years of trials that the FDA requires.
It looks like this is the medical breakthrough that everyone dreams about: a true cure for cancer. Except this time it's widely available and not that painful.