FEATURE | Posted Sept. 8, 2015

Man’s best friend may also be his best weapon against cancer

A couple of rambunctious puppies are in training to use their keen sense of smell to find cancer

Photo of puppies Alfie and Charlie, to be trained to sniff out cancer © UC Regents
Cancer detection dogs-in-training Charlie and Alfie are introduced to the media at the UC Davis Comprehensive Cancer Center.

Alfie, a labradoodle, and Charlie, a German shepherd, have taken up residence with two UC Davis physicians while undergoing a rigorous 12-month training program to develop their abilities to identify the scent of cancer in saliva, breath and urine. Scientists hope to find the cancer chemicals that only dogs can smell then use that understanding to develop technology capable of detecting cancerous tissue.

Such an advance in cancer detection would help physicians detect cancer early when it is more easily treated and cured. Cancer is the second leading cause of death in the United States.

Dogs' keen sense of smell

The olfactory acuity of dogs enables them to detect odorant concentration levels at 1 to 2 parts per trillion, roughly 10,000 to 100,000 times that of a human, according to sensory scientists.

UC Davis physicians and researchers believe Alfie and Charlie have the potential to add an important diagnostic element to patient care. The introduction of the cute canines in early August sparked national interest, as dog-lovers, scientists and others interested in their potential to help in the fight against a devastating disease.

Puppy Charlie with Dr. Ralph de Vere White © UC Regents
UC Davis Comprehensive Cancer Center director Ralph de Vere White gives Charlie a dog-lover’s welcome.

Although the dogs are not being trained to work in cancer clinics, UC Davis Comprehensive Cancer Center Director Ralph de Vere White acknowledges dogs’ special gifts.

“For the past number of years, we have been developing very high-end, expensive new tests to try and detect the presence of cancer,” he said. “Dogs have been doing this, for example, detecting disease in the urine of people suspected of having bladder cancer. This work marries sophisticated technology with low-tech, yet sophisticated, dogs’ noses to see if they can help us identify the molecules that differentiate cancer from non-cancer.”

Advancing early cancer detection

Hilary Brodie, professor and chair of the UC Davis Department of Otolaryngology, hopes that the identification of these molecules will lead to innovative and readily available methods of detection.

“Much like the hand-held devices used to detect alcohol, drugs and explosives have revolutionized our safety, having a new tool to detect early-stage cancer would have incredible benefits for patient care,” noted Brodie, whose department treats head, neck and throat cancer patients.

Researchers have established that dogs can recognize melanoma as well as bladder, lung, breast and ovarian cancers. Canines have been successfully trained to distinguish the breath samples of lung and breast cancer patients from those of healthy volunteers. Such promising results have cancer experts at UC Davis enthusiastic about the potential for the dogs to represent a safe, noninvasive method for detecting cancer before it is too late.

Dr. Brody and puppy Alfie © UC Regents
Hilary Brodie, professor and chair of the UC Davis Department of Otolaryngology, visits with Alfie.

“Identifying patients at earlier stages could be extremely helpful in the fight against cancer,” said Gregory Farwell, professor of otolaryngology and director of the university’s Head and Neck Oncology and Microvascular Surgery program.

Alfie and Charlie are being trained by Dina Zaphiris, director of the In Situ Foundation in Chico, Calif. Zaphiris has trained more than two-dozen dogs to detect cancer. The UC Davis canines are currently learning to distinguish samples from cancer patients and healthy individuals. Zaphiris said almost any dog can be trained to detect cancer, but she prefers German shepherds, Labradors, poodles and herding breeds because of their work ethic.

Future clinical trial

Alfie and Charlie’s human-cancer screening work will begin in early 2016 with a clinical trial to establish the safety and efficacy of the new diagnostic approach. UC Davis physicians say their ultimate goal is to bring more comprehensive cancer-screening capabilities to the public.

“Despite all the advances of modern medicine, we still can’t reliably detect many types of cancers in their early stages,” said Peter Belafsky, professor of otolaryngology and a physician who often deals with cases involving advanced cancer. “Our new canine colleagues represent a unique weapon in the battle against cancer. It’s the first of its kind at UC Davis, and the dogs’ incredible talent for scent detection could offer us humans a real jump on diagnosing cancer much earlier and thus save many more lives.”