A urine test developed by researchers at the Nagoya University in Japan can pinpoint a person who has a brain tumor — regardless of its size or malignancy — with 100% accuracy, according to a new study.
Decorated with 100 million zinc oxide nanowires, the test works by plucking tiny molecules called microRNAs from just a millimeter of urine in much greater quantities and varieties than traditional tests.
It can be sterilized, produced on massive scales and completed by patients any time anywhere with “minimal effort,” according to the study published recently in the journal ACS Applied Materials & Interfaces.
The test’s non-invasive nature and easy handling could help to earlier detect and treat aggressive brain tumors, which go largely unnoticed until symptoms appear and have grown too large to be surgically removed, eventually improving brain cancer patient survival.
“Urine can be collected easily without putting a burden on the human body,” study corresponding author Dr. Atsushi Natsume said in a statement. “Urine-based liquid biopsy hadn’t been fully investigated for patients with brain tumors, because none of the conventional methodologies can extract microRNAs from urine efficiently in terms of varieties and quantities. So, we decided to develop a device capable of doing it.”
Past research has shown that microRNAs lodged in blood can be used for cancer screening, but studies on how these tiny revealing molecules from tumors in the brain fare in urine have been lacking. Part of the challenge lies in a stubborn blood-brain barrier that strictly limits what’s cruising in your bloodstream, such as potential toxins and disease-causing germs, from entering your brain.
But the team’s new test revealed microRNAs born in brain tumors can make their way to urine and exist “in a stable condition,” suggesting there are other ways besides expensive CT or MRI scans to detect brain cancer before it’s too late.
A total of 119 urine and tumor samples were collected from patients with central nervous system (CNS) cancers admitted to 14 hospitals in Japan between March 2017 and July 2020. Researchers used 100 urine samples from people without cancer to serve as a control for their test and a model they created based on the expression of microRNAs in pee.
The diagnostic pair was able to detect samples belonging to people with brain tumors with 100% sensitivity (its ability to identify those with cancer) and 97% specificity (its ability to identify those without cancer), regardless of the tumor’s size or state.
Cancer mortality rates over the last two decades have been on a steady decline, likely because of advances in early detection and treatment, but those for CNS tumors have not, the researchers said. “This is partly because hardly anyone will undergo regular medical checkups for CNS tumors until the tumors spread and neurological deficits are presented,” such as speech problems or immobile limbs.
“In the future, by a combination of artificial intelligence and telemedicine, people will be able to know the presence of cancer, whereas doctors will be able to know the status of cancer patients just with a small amount of their daily urine,” Natsume said.