A simple urine test just outperformed the standard tools for catching bladder cancer — and it might also tell doctors which treatment will work. The test, called uRARE-seq, was developed by a Stanford Medicine and VA Palo Alto Health Care System team, and the results, published October 2 in Nature Medicine, are the kind that change how a disease gets managed.

Here’s the headline number: across 683 urine samples from patients and healthy volunteers, the test correctly identified 95% of localized bladder cancers and correctly classified 90% of people without cancer. It beat both standard urine cytology and a DNA-based urine test. That’s not an incremental improvement. That’s a new bar.

Why RNA, not DNA

The clever part is what the test measures. Most liquid biopsies look at DNA — the mutations a tumor carries. uRARE-seq looks at cell-free RNA, the messages tumor cells shed into urine. DNA tells you what’s broken. RNA tells you what the cancer is actively doing: which genes it’s using, how aggressive it’s being, how it’s responding to its environment.

That difference is what unlocks the test’s second trick. The RNA profile can distinguish low-grade from high-grade disease, detect residual cancer after surgery or BCG therapy, and — most strikingly — predict who will respond to BCG immunotherapy versus who needs chemotherapy sooner. The RNA of responders is rich in T-cell and immune-signaling genes; the test can see the immune system gearing up before the clinical outcome is visible.

That last part matters more than it sounds. BCG has a single global supplier and suffers frequent shortages. Right now, doctors can’t always tell who benefits most from the limited supply. A test that triages patients to the right therapy isn’t just a diagnostic — it’s a rationing tool for a scarce drug.

The surveillance problem it solves

Bladder cancer is one of the most expensive cancers to manage, and the reason is surveillance. About 85,000 Americans are diagnosed each year, and after treatment, patients undergo cystoscopy — a camera inserted into the bladder — as often as every three months for years. It’s invasive, it’s uncomfortable, and it still misses up to 30% of cases.

A noninvasive urine test with 95% sensitivity changes that calculus. Fewer scopes, earlier catches, better triage. For patients, that’s fewer awful mornings in a urology clinic. For the health system, that’s real money saved on the most surveillance-intensive cancer there is.

What happens next

Lead author Kevin J. Liu, a Stanford graduate student, and senior authors Maximilian Diehn, Joseph Liao, and Ash Alizadeh have already taken the commercial step: Stanford spinoff Resero Bio, based in San Carlos, has been formed to bring the test to market, patents are filed, and larger multi-center prospective trials are planned. That’s the right sequence — a strong single-center result, now validated at scale.

Cancer screening has had a remarkable run lately, from promising Alzheimer’s prevention research to ever-better liquid biopsies. uRARE-seq belongs in that company: a test that doesn’t just find cancer earlier, but helps doctors treat it smarter. For the 85,000 people diagnosed each year, that’s the kind of progress that actually changes lives.