Trained dogs can spot aggressive prostate cancers by detecting trace amounts of chemical biomarkers in urine samples, says a new study. The researchers describe the utility of a new multisystem approach that combines the powerful sensitivity of dogs’ noses with complementary chemical analytical techniques and artificial intelligence, ultimately delivering a highly sensitive and accurate means of diagnosing prostate cancer.
The study was published in PLOS One.
The American Cancer Society estimates that nearly 250,000 men in the United States will be diagnosed with prostate cancer in 2021 alone, the second leading cause of cancer mortality among men. Earlier interventions can save lives, but clinicians still lack the tools to be able to achieve this. Improvements to the way prostate cancer is diagnosed and classified can help patients with more aggressive, metastatic forms of the disease get the help they need sooner.
For now, the standard prostate-specific antigen, or PSA test, is routinely used, despite it being notoriously unreliable for accurate prostate cancer diagnoses.
A study led by Alan Partin, a urologist at Johns Hopkins Hospital, has described how dogs can learn to respond to cancer biomarkers in urine to aid in prostate cancer diagnostics.
Two dogs, a 4-year-old Lab called Florin and Midas, a 7-year-old wirehaired Hungarian vizsla, were trained to signal their handlers when they smell volatile organic compounds. These chemicals are produced during cancer cells’ metabolism and secreted in the urine, and have been established as cancer biomarkers for diagnostic purposes.
“Besides PSA, other methods to detect prostate cancer make use of a molecular analyzer called a gas chromatography-mass spectrometer [GC-MS] to find specific VOCs or profiling bacterial population in a urine sample looking for species associated with cancer, but these have limitations,” explained Partin.
Partin and colleagues found that this combination of diagnostics significantly improved the diagnoses of high-grade prostate cancer, allowing the researchers to pinpoint which of the 1,000 VOCs present in typical urine samples were associated with the disease.
The researchers say that these findings pave the way for future technologies to detect prostate cancer earlier, in a non-invasive manner, with superior sensitivity and specificity to the current gold standard.