It’s not every day that a team of researchers sets out to beat dogs at their own game.
But Wen-Yee Lee, an associate professor of chemistry at the University of Texas at El Paso, and her team have spent the last few years trying to do just that. They are researching methods to detect prostate and kidney cancer from urine samples, something that trained dogs can do naturally – and accurately – through smell.
The research was published in the June issue of the Clinical Genitourinary Cancer peer-reviewed journal.
“If dogs can do it, then we can do better,” Lee said.
Right now, one of the most common tests for prostate cancer is the prostate-specific antigen blood test, better known as the PSA test. But prostate cancer is hard to detect, and the test has a high error rate, which can lead to unnecessary biopsies and treatments.
Lee and her team are developing a more accurate, less invasive test. Lee said she got the idea to research and identify cancerous metabolites in urine after reading a paper around 2012 about how trained dogs can detect cancer by sniffing urine samples.
If dogs could smell something, Lee reasoned, it means there are gas molecules present, possibly including metabolites from cancerous cells.
Metabolites are the end product of the metabolization process. The small molecules can be present in substances like gas and are often used to study the side-effects of prescription drugs, or to detect drug usage through a urine test.
Lee’s research focuses on detecting and identifying metabolites in urine from cancerous cells. After the metabolites are detected and identified, the data is run through a machine-learning algorithm that uses big data mining to deliver a score.
“Based on that score, we can apply a cutoff point,” Lee said. “Above a certain number, this patient is likely to have cancer. If it’s below, they’re less likely.”
If dogs are so good at sniffing out cancer, why aren’t they used more? They have to be highly trained, and there are few of them. And sniffing urine samples is hard work – even for a dog.
The ultimate goal for Lee’s research is to replace the PSA test. She said the test is less accurate than many patients realize, at about 50%. Lee’s technology currently has a 92% accuracy rate, she said.
Lee said she wanted to create a test that is both affordable and accessible for patients. Requirements for collecting urine are less strict than blood, and the process is less invasive than a needle draw. Lee added that each run of the test only requires a milliliter of urine.
Lee presented her research at a demo day at the Medical Center of the Americas last month, winning the audience choice prize for her elevator pitch. She said her team has not yet reached out to local hospitals and doctors to start using the technology, but they hope to do so in the future.
Although Lee and her team have been researching for years, the project still needs to go through additional validation. Lee said they’ve worked with about 150 urine samples so far, but need between 600 to 1,000 additional samples for the work to be validated.
There are several doctors and labs that Lee goes to for urine samples, not all from El Paso. She said she hopes to increase the number of samples she receives by putting out a call for samples, but she first needs approval from UTEP’s internal review board.
Qin Gao, a postdoctoral researcher, works on the project with Lee. Gao graduated from UTEP this spring with a doctorate in chemistry, and said she hopes the urine test will be able to help detect cancer at an accessible price.
“We do want to help with cancer screening and want our project to be helpful for everyone,” Gao said.
Both Lee and Gao have previous experience researching small molecules. Lee is an analytical chemist who studies organic pollutants in soil, air and water. Gao had previously worked on examining metabolites in a pharmacological setting.
Lee and Gao hope the technology can be used one day for non-invasive monitoring of cancer levels in patients who may not immediately need tumors surgically removed.
“In the past, a lot of doctors were recommending surgery for all prostate cancer patients,” Lee said. “Now they’re thinking not everyone needs surgery and can do active surveillance. A reliable monitoring test will be very, very important.”
Email El Paso Inc. reporter Sara Sanchez at firstname.lastname@example.org or call (915) 534-4422, ext. 105.