New research paves way for bladder cancer urine screens

Screening patients for bladder cancer could soon be as easy—and painless—as an at-home pregnancy or Covid-19 test, thanks to the recent discovery of proteins that signal the disease’s early stages.

University of Houston (UH) researchers, who analyzed more than 1,300 urine sample proteins from 2020 to 2023, identified biomarkers that could help doctors detect and diagnose the disease via a simple urine test instead of a cystoscopy—an invasive procedure in which a thin camera is inserted into a patient’s urethra.

Chandra Mohan, a Hugh Roy and Lillie Cranz Cullen endowed professor of biomedical engineering at UH and the study’s lead author, told Healthcare Brew that more research is needed before a urine test can replace cystoscopy as the “gold standard” for bladder cancer diagnosis. But if adopted, the method could improve early detection of bladder cancer—one of the most common cancers diagnosed in the US—as well as patient outcomes and medical costs.

“It’s rare for somebody to send a patient for cystoscopy unless the index of suspicion [of cancer] is very high. This is a test that all you need is a urine sample. The chances are this will be done much earlier in larger numbers of patients…resulting in better identification—early identification—of bladder cancer,” Mohan said. “Of course, they would confirm that using a cystoscopy and biopsy.”

The study, which Mohan said was the first to examine such a wide range of urine sample proteins for potential biomarkers, found that one protein fragment, D-dimer, could play a role in cancer diagnosis or recurrence detection. D-dimer displayed the highest accuracy and sensitivity—at a respective 96% and 97%—of 21 urine proteins discriminating bladder cancer from urology clinic controls during the screening.

Researchers also found eight urine proteins that discriminated between muscle invasive bladder cancer—which spreads into deeper layers of the bladder, like the bladder wall—and non-muscle invasive bladder cancer that stays in the mucosa. Of those, the proteins/markers IL-8 and IgA were the best performers and “may have the potential in identifying disease progression during patient follow-up,” according to the report.

Noninvasive urine screening tests already exist for bladder cancer, Mohan said. However, they are generally less accurate (ranging from 40% to 80%) than cystoscopy and look at cells, DNA/RNA molecules, or proteins—but not the new biomarkers identified by UH researchers.

Mohan said researchers plan to conduct a larger validation test of the newly discovered biomarkers in larger numbers of patient urine samples, as well as develop point of care tests—similar to at-home Covid-19 tests.

“We have the technology,” he said. “But we are seeking funds to ramp this up.”