For years, scientists have been using dogs' incredible sense of smell as inspiration for the development of new-age diagnostic devices. This could have a real impact on the detection of prostate cancer, where current methods involve rather uncomfortable procedures. Scientists are now reporting a promising advance in the area, identifying key molecules in the scent of urine that seem to reveal prostate cancer in the subject.

Diagnosis of prostate cancer starts with a blood test to evaluate PSA levels (prostate-specific antigen). This protein is produced by the prostate in small amounts, and when levels are heightened it can be indicative of prostate cancer in which case a biopsy often follows to remove tissue from the gland for further analysis. But there are limitations to this approach, mainly because increased PSA levels can be triggered by other conditions, such as prostate infection, for example, and therefore lead to a great number of unnecessary biopsies.

"Currently, about 60 percent of men who get a biopsy to test for prostate cancer don't need to get one," says Amanda Siegel from Indiana University-Purdue University Indianapolis, who is presenting the new research today at the 253rd meeting of the American Chemical Society. "We hope our research will help doctors and patients make better-informed decisions about whether to have a biopsy, and to avoid unwarranted procedures."

The team's work started following a 2014 study that revealed trained dogs could detect prostate cancer in urine. It set out to determine which molecules arising from a urine sample could reveal prostate cancer in the subject. This involved gathering 100 urine samples from men undergoing prostate biopsies. Using a technique called gas chromatography-mass spectrometry to identify and quantify individual volatile organic compounds, the team zeroed in on a small set. These appeared in 90 percent of samples taken from patients with prostate cancer, but not in those without it.

Armed with what appears to be a reliable molecular signature for the disease, the team is now planning to carry out large-scale tests at a series of health centers to validate the findings. It will also try and team up with dog trainers to compare the technique to that of an actual canine nose.

If these next steps play out as hoped, the researchers say the test could be available to patients in the next few years, though in its initial form this would require urine samples to be sent off to the lab. Eventually, the researchers hope to develop a sensor that can offer results right then and there in the doctor's office.