Urinary genomic test demonstrates utility in cystoscopy decision-making

Findings from the STRATA trial (NCT03988309) show that use of Cxbladder Triage resulted in a reduction in the number of cystoscopies performed for patients with lower risk asymptomatic microscopic hematuria vs standard of care, supporting use of the mRNA based urinary genomic test for clinical decision-making in this patient population.¹

Cxbladder demonstrated a sensitivity of 0.90 and a specificity of 0.56.

Data from the study were presented at the 2024 American Urological Association (AUA) Annual Meeting in San Antonio, Texas by Yair Lotan, MD.

Lotan noted during the presentation, “I think it's important to point out that even though this might seem self-evident, there have been many urine markers studies retrospectively showing very good performance in patients that have not subsequently resulted in any change in recommendations, guidelines, or utilization in a hematuria population prospectively.”

For the current study, 135 patients were classified as low-risk (3 to 29 RBC/hpf and minimal smoking history) and were randomly assigned to the Cxbladder arm (n = 81) or to the control arm (n = 54). Overall, data showed that patients in the Cxbladder arm had a 59% relative reduction in the number of cystoscopies performed vs those in the control arm.
Specifically, in the Cxbladder arm, 87.7% of patients (71/81) received a negative result for urothelial cancer, and 19.7% of those (14/71) chose to have a cystoscopy. Of the remaining patients in the Cxbladder arm who received a positive result, 80% (8/10) chose to have a cystoscopy. In the control arm, 67% of patients (36/54) patients received a cystoscopy, though Lotan noted that according to standard of care, all patients should have received one.

Of the 57 patients in the low-risk Cxbladder arm with a negative result who chose not to have a cystoscopy, 48 patients had some follow-up data. Only 1 patient who initially had a negative Cxbladder result received a positive result on a subsequent test administered 13 months later.

Among all evaluable patients (n = 270), Cxbladder demonstrated a sensitivity of 0.90 (95% CI, 0.70-0.99) and a specificity of 0.56 (95% CI, 0.49-0.62). The negative predictive value for the test was 0.99 (95% CI, 0.95-1.0) and the positive predictive value was 0.15 (0.09-0.22).

Lotan noted, “That's not unexpected; the test is really designed to optimize the negative predictive value. And don't forget, these were patients who were supposed to get cystoscopy in the first place, so even if they did end up getting a cystoscopy, it wasn't something that would have otherwise been not done.”

Overall, the prospective, multicenter STRATA study included patients with hematuria who provided urine for Cxbladder testing. In the study, low-risk was defined as 3 to 29 RBC/hpf and minimal smoking history (less than 10 pack years). The authors noted that since this study was conducted prior to the AUA guidelines, some patients who met the criteria for low risk in the study would be considered to be in a different risk stratification group according to the guidelines.

Lotan explained, “There was some overlap in the lower risk because we didn't use age stratification; some of them would have been high-risk, and many of them would have been intermediate-risk.”

Among all those included in the study, the average age was 60.1 years (SD, 14.7). The primary objective for the trial was to compare the rate of cystoscopy among low-risk hematuria patients who received a Cxbladder test result vs standard of care. The secondary objective was to evaluate the accuracy of the test among patients who received a subsequent biopsy.

Overall, the authors concluded, “This demonstrated clinical utility of Cxbladder Triage can help reduce the burden of unnecessary cystoscopies in this population resulting in less patient morbidity and discomfort, improved access to care, and reduced environmental impact.”¹

References

1. Lotan Y, Daneshmand S, Shore N, et al. A multicenter prospective randomized controlled trial comparing cxbladder triage to cystoscopy in patients with microhematuria. J Urol. doi:10.1097/01.JU.0001008576.33217.96.08