A group of Japanese researchers recently announced in a science journal an economical and highly accurate cancer detection method that makes use of roundworms about 1 mm long that can identify cancer patients by sensing odors in urine.

The researchers, including Takaaki Hirotsu, assistant professor at Kyushu University, said the cancer screening test, which is painless, will cost between ¥100 and several hundred yen each time and deliver results in about 90 minutes.

The group is also working with Hitachi Ltd. and others to develop a screening device for the test, hoping to put it into practical use as early as 2019. It announced the findings Wednesday in the U.S. online journal PLOS ONE.

The group said the method could enable the detection of early-stage cancers that cannot be spotted by conventional tests, and encourage people to undergo screening and treatment earlier.

“If you send a drop of urine taken at home to a testing institution, you can detect your cancer. This will also help curb medical costs,” Hirotsu said.

Previous reports have shown that cancer can be detected with high accuracy by dogs or mice, but introducing scent detection into clinical practice has been difficult because its accuracy is influenced by the dogs’ concentration levels, the study said.

But the researchers found that nematodes, which live in soil or water, are attracted to the urine of cancer patients and avoid the urine of healthy people.

They tested 242 urine samples to measure the performance of what they call a Nematode Scent Detection Test and found the sensitivity was 95.8%, which is markedly higher than the tumor-marker diagnosis tests conducted with blood samples.

They also noted that the urine test identified five cancer-positive participants, even though they were not categorized as such when their urine was obtained in 2011.

Their cancers were detected over the next two years.

“Importantly, this test was able to diagnose various cancer types tested at the early stage. To conclude . . .(these) scent-based analyses might provide a new strategy to detect and study disease-associated scents,” the researchers said in the online journal.

Currently, the testing method cannot identify what type of cancer the patient is suffering from, but the researchers have succeeded in cultivating nematodes that react to certain cancers.

KEYWORDS cancer