Since 2004, research has begun to accumulate suggesting that dogs may be able to smell the subtle chemical differences between healthy and cancerous tissue, including bladder cancer, melanomaand cancers of the lung, breast and prostate. But scientists debate whether the research will result in useful medical applications.
Dogs have already been trained to respond to diabetic emergencies, or alert passers-by if an owner is about to have a seizure. And on the cancer front, nonprofit organizations like the In Situ Foundation, based in California, and the Medical Detection Dogs charity in Britain are among a growing number of independent groups sponsoring research into the area.
The next step will be to build a mechanical, hand-held sensor that can detect that cancer chemical in the clinic. That’s where Charlie Johnson a professor at Penn who specializes in experimental nanophysics, the study of molecular interactions between microscopic materials, comes in.
He is developing what he calls Cyborg sensors, which include biological and mechanical components – a combination of carbon nanotubes and single-stranded DNA that preferentially bond with one specific chemical compound. These precise sensors, in theory, could be programmed to bind to, and detect, the isolated compounds that Dr. Otto’s dogs are singling out.
“We are effectively building an electronic nose,” said Dr. Johnson, who added that a prototype for his ovarian cancer sensor will probably be ready
Some experts remain skeptical.