A study may soon be under way in England to determine whether dogs can sniff out prostate cancer. Researchers at Cambridge University plan to train three dogs to detect the signature odor of prostate cancer cells found in a patient's urine. If dogs can be trained to accurately detect cancer cells, they may offer a fast, inexpensive way to screen patients for prostate cancer, especially in countries with limited access to lab testing.
Although rigorous studies are lacking, anecdotal evidence suggests that dogs, whose sense of smell is 1,000 to 100,000 times more sensitive than ours, readily recognize the distinctive odors of cancerous tissue. In a letter to The Lancet in 1989, a physician described a dog who alerted his owner to a malignant growth on her leg. Subsequently, a dermatologist in Florida, working with a police dog handler, trained dogs to detect melanoma in containers and on patients' skin, reportedly with near-100% accuracy.
Experts caution that to meet the standard for a cost-effective screening test, researchers will have to prove that the dogs are accurate nearly every time.