New research from an international team of scientists – and two specially trained dogs – have scientifically validated the ability for man’s best friend to ‘sniff-out’ prostate cancer in men – more accurately than the electronic nose (e-nose), an artificial sensing device used to detect odors and flavors.
For decades, law enforcement and the military have used dogs to help locate bombs and drugs. It should then be no surprise that a dog’s intricate sense of smell has captured the interest of the medical world. In recent years, new findings have emerged to indicate dogs are capable of accurately detecting the onset of epileptic seizures .as well as malignancies of the breast and lung.
While humans have roughly five million olfactory cells in their noses, dogs have about 200 million. While it is still unknown what the dogs are actually able to smell, researchers do believe they are able to pick up the odor of volatile organic compounds (VOCs), which are released into the urine by prostate tumors.
Researchers investigated the level of accuracy at which two highly-trained explosion detection German Shepard dogs can recognize prostate cancer-specific VOCs in urine samples compared to a new type of e-nose specifically developed to detect prostate cancer.
The study consisted of 126 participants who were placed in one of two groups: a prostate cancer group (n=66) and a control group (n=60). The prostate cancer group was exclusive to men with prostate cancer, ranging from early stage to late state disease. The control group included both men and women, some of which had cancer, some who did not, but no one within the control group had prostate cancer.
- The two dogs were able to detect VOCs in the urine of the study subjects with an accuracy of nearly 98 percent. Sensitivity and specificity for each German Shepard were nearly 99 percent and 98 percent respectively.
- The e-nose was able to detect prostate cancer with an accuracy of 84 percent. Sensitivity and specificity were 85 percent and 82 percent respectively.
- When only men aged 45 years were considered, the two dogs were able to detect prostate cancer with an accuracy of nearly 99 percent while the e-nose had an accuracy level of 82 percent.
“We all know the sense of smell is a superpower for dogs,” said Dr. Loeb. “Seeing this superpower put to the test against advanced technology is fascinating. In a world full of technology, it appears dogs are better able to naturally screen for prostate cancer than our most advanced technology. Hopefully science and technology can learn more from them in the near future and finally catch up.”
The full abstract of this study can be viewed here. The study was presented during a virtual press session, which was moderated by AUA spokesperson, Dr. Stacy Loeb, urologic oncologist at NYU Langone Health and the Manhattan Veterans Affairs.