A simple urine test could accurately show the recurrence of kidney cancer at an early stage, potentially sparing patients invasive scans and enabling faster access to treatment, new research has shown.
The findings are presented today [Monday 24 March 2025] at the European Association of Urology (EAU) Congress in Madrid and have been accepted for publication in European Urology Oncology.
The test analyses the distinctive profiles of certain types of sugar molecules, called glycosaminoglycans which are found in urine. These profiles are known as the GAGome.
The international AURORAX-0087A (AUR87A) study is assessing whether a GAGome test can accurately detect the return of clear cell renal cell carcinoma (ccRCC) following surgery. This is the most common form of kidney cancer and accounts for up to 90% of cases. There are around 400,000 patients diagnosed with ccRCC worldwide each year.
Around one-fifth of ccRCC patients who have surgery to remove their cancer will see it return within five years – the majority within the first two years. Currently, the only way to monitor patients is through a scan – usually a CT scan – every 6 to 12 months, with the frequency depending on their level of risk.
The study's initial cohort involved 134 patients treated at 23 hospitals across the UK, EU, USA and Canada. The patients were all diagnosed with ccRCC which had not spread beyond the kidney, and which was treated with surgery. Most had their kidney completely removed. All patients continued to have CT scans as standard monitoring after surgery, alongside a urine test every 3 months. Each urine sample was analysed using mass spectrometry to produce a score out of 100, called the GAGome score.
After up to 18 months of follow up, 15% of patients had seen their cancer return. The GAGome test was extremely sensitive in picking up recurrence, correctly identifying 90% of patients whose cancer had returned, while correctly ruling out just over half of those who remained cancer-free. These results were based on a GAGome score threshold optimised at 12/100. A score above 12 was counted as positive, and 12 or below as negative.
A positive result in the study yielded a 26% chance the patient actually had a recurrence. More importantly, a negative GAGome score resulted in a highly reliable 97% chance that the patient did not have a recurrence. The higher the GAGome score, the more likely the positive result correctly identified recurrence.
This level of accuracy is similar to CT scans and offers advantages to using scans alone, according to lead researcher on the study, Saeed Dabestani, Associate Professor at Lund University and Consultant Urologist at Kristianstad Central Hospital, Sweden.
"CT scans often pick up small lesions that aren't large enough to biopsy, and we currently don't know whether they are a sign of the cancer returning or not," he explained. "Our only option is to do more frequent scans to monitor more closely, which is unpleasant for patients and often brings little benefit.
"If you have a urine test that can accurately show whether the cancer has actually returned then you can better assess risk levels and reduce the frequency of the scans required. Based on the results we have so far, it's likely that we could safely halve the number of scans that patients have to undergo."
Dr Carmen Mir Maresma, Consultant Uro-Oncologist from University Hospitals La Ribera in Valencia, Spain, and member of the EAU Scientific Congress Office said: "Developing biomarkers for kidney cancer is a major challenge and this study provides a stepping stone towards that goal. The results are really interesting, in that the test showed a high negative predictive value. If the test comes back negative, you can be more or less sure there is no cancer recurrence, but if it's positive, then we need to look further. The test is also based on a suite of biomarkers, rather than just one molecule, which provides a more robust basis for making decisions on treatment.
"We don't know yet whether finding recurrence sooner will save patients' lives – more research is needed to determine that. There are also changes in post-operative treatment underway, with some countries licensing the immunotherapy pembrolizumab for kidney cancer. More research will also be needed to understand how this biomarker interacts with that therapy."
The international team involved in the AUR87A study is nearing final recruitment of the second cohort of patients, the results from which will be used to validate the findings from the first cohort. These results are expected towards the end of this year.
The GAGome test used in the AUR87A study is under development by Swedish diagnostics company, Elypta, for whom Dabestani also acts as a medical adviser. The test has not yet been approved for clinical use in diagnostic procedures and further research will be required to confirm its effectiveness in clinical practice.
