Researchers at Houston's Memorial-Hermann Cancer Center say using the body's own immune system to fight cancer is promising now, after years of work.  Dr. Robert Amato is the center's director.  He says the most important recent development is engineering T-cells to recognize cancer cells.

“The T-cells activate, they bind to the cancer cells, recognizing they are foreign,” he explains, “and the immune system does its role, activating further immuno-components.”

In the past, immunotherapy has been limited in its effectiveness because the surface of the cancer cells has been hard to identify, so the immune system will do its job.

Dr. Amato won't call this a cure -- yet.

“I would refrain from using the word cure, but it potentially could evolve in that direction,’ he says, “because we all believe if we can harness the immune system, that those are the opportunities for curing cancer.”

Doctors say the strength of your own body’s immune system far surpasses the benefits offered by drugs and chemotherapy.

Another positive thing -- these therapies don't cause bad side effects.