From Hopkins Newletter

[Guest guest]

Prostate Cancer Testing Goes to the Dogs

In the quest to come up with a highly sensitive and highly specific prostate cancer test that will predict with the utmost accuracy whether or not a man has prostate cancer, "man's best friend" -- the dog -- is being brought in to sniff out prostate cancer cells found in urine. The results of a small French study presented at the American Urological Association (AUA) meeting have been quite impressive so far.

We know from previous work that cancer cells emit different metabolic wastes when compared to healthy cells and that their particular odor is so different that it can be detected and differentiated by a trained dog. Over the past decade, specially trained dogs have been used in experiments to sniff out skin, lung, bladder, and breast cancers.

In the recent study presented at the AUA, Jean-Nicolas Cornu, M.D. and fellow researchers from Tenon Hospital in Paris, used fresh urine samples from 66 men who had been referred to a urologist because they had elevated PSA and abnormal DRE (digital rectal exam) findings. Half of the men had prostate biopsy-detected cancer and half were cancer-free. Using a Belgian Malinois -- a working shepherd breed with a keen sense of smell that has been used in previous cancer tests -- the French researchers had the dog identify urine from men with the biopsy-confirmed prostate cancer. The dog was specially trained to detect and correctly identify certain prostate cancer cell-derived volatile organic compounds (VOCs) in urine.

Dr. Cornu believes that these data suggest that prostate cancer tumors may excrete certain VOCs that are present in a patient's urine and that this particular "scent" may be very specific to prostate cancer. The next step is to determine what those particular VOCs are and whether or not a specific test can be developed to identify them very early in the testing phase.

While this French research is certainly impressive, scientists at many leading medical centers here and abroad are currently at work on various prototypes of "electronic noses," sophisticated diagnostic devices they hope eventually will outdo even a dog's sensitive nose in signaling the presence of VOCs produced by prostate cancer cells. The ENose, which typically uses nanotechnology and multiple polymer films to pick ups scents, will be programmed to recognize almost any molecule or combinations of molecules. It's hoped that with this new technology, doctors will be able distinguish prostate cancer VOCs from non-cancer VOCs, something that the talented Belgian dog can now do -- but can't explain to the researchers.