Dogs Can Smell Lung Cancer.

The evidence is rapidly accumulating that dogs can smell some forms of cancer.  In a recent study, dogs were trained to identify lung cancer by smelling exhaled breath samples from patients.  They were able to identify 71% of the lung cancer samples and were not confused by samples from patients with other lung disorders.  The results indicate that lung cancer cells produce a chemical that ends up in exhaled breath.  Unfortunately, the dogs were not able to tell the researchers the identity of that chemical.