Cancers are out of control cells that have their own unique chemistry. They also release organic compounds into the body. A team at the University of Arkansas for Medical Services has been able to train a dog to smell these compounds released by the cancer cells. The dog, a German shepherd, was able to sniff out thyroid cancer in people who had not yet been diagnosed. The dog gave the correct diagnosis in 30 out of 34 cases or 88 percent. The Arkansas team had already shown that a dog could be trained to smell the difference in urine samples between patients who had thyroid cancer and those who did not. The research could lead to new, cheaper, and less painful approaches to cancer diagnoses.