A simple urine test could accurately detect clear cell renal cell carcinoma (RCC) recurrence at an early stage, potentially sparing patients from undergoing invasive scans and enabling quicker access to treatment, according to new findings presented by Dabestani et al at the European Association of Urology (EAU) Congress 2025 (Abstract GC10).
Background
Clear cell RCC is the most common type of renal cancer, accounting for up to 90% of cases. About 400,000 patients are diagnosed with the disease across the world each year. Around 20% of patients with clear cell RCC who undergo surgery to remove their cancer will see it recur within 5 years—the majority of which recur within the first 2 years. Currently, the only strategy to monitor patients is through a computed tomography (CT) scan performed every 6 to 12 months, with the frequency depending on their level of risk.
“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. Our only option is to do more frequent scans to monitor more closely, which is unpleasant for patients and often brings little benefit,” explained lead study author Saeed Dabestani, MD, PhD, Associate Professor at Lund University and a consultant urologist at Kristianstad Central Hospital in Sweden.
GAGome tests analyze the distinctive profiles of certain types of sugar molecules called glycosaminoglycans found in the urine.
Study Methods and Results
In the international AURORAX-0087A study, researchers assessed whether a GAGome test could accurately detect cancer recurrence following surgery among 134 patients with localized clear cell RCC. Most of the patients had their kidneys completely removed, and all of the patients continued to undergo CT scans as standard monitoring postsurgery, alongside a urine test every 3 months. The patients were treated at 23 hospitals across the United States, United Kingdom, European Union, and Canada.
Each urine sample was analyzed using mass spectrometry to produce the GAGome score, which was measured out of 100. The results were based on a GAGome score threshold optimized at 12/100; a score above 12 was counted as positive, whereas a score at 12 or below was deemed negative.
After a follow-up of 18 months, the researchers found that 15% of the patients had had a clear cell RCC recurrence. The GAGome test was extremely sensitive in picking up recurrence, correctly identifying 90% of those whose cancer had recurred, while correctly ruling out just over 50% of those who did not experience cancer recurrence.
The researchers noted that a positive result in the study yielded a 26% risk that the patient had cancer recurrence. Notably, a negative GAGome score resulted in a highly reliable 97% likelihood that the patient didn’t have cancer recurrence. The higher the GAGome score, the more likely the positive result correctly identified recurrence. This level of accuracy was comparable to CT scans and offered advantages to using scans alone.
Conclusions
“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. Dabestani indicated.
The researchers are currently 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 at the end of 2025.
“Developing biomarkers for [renal] cancer is a major challenge, and this study provides a stepping stone toward that goal. The results are … 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,” underscored Carmen Mir Maresma, MD, PhD, FEBU, a consultant uro-oncologist at the University Hospitals La Ribera in Spain and a member of the EAU Scientific Congress Office. “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 postoperative treatment underway, with some countries licensing the immunotherapy pembrolizumab for [renal] cancer. More research will also be needed to understand how this biomarker interacts with that therapy,” she concluded.
The GAGome test has not yet been approved for clinical use in diagnostic procedures. Further research will be required to confirm its effectiveness in clinical practice.
Disclosure: For full disclosures of the study authors, visit urosource.uroweb.org.
