Introduction:

Patients with non-muscle invasive bladder cancer (NMIBC) often experience recurrence and require frequent surveillance to rule out disease. Frequent cystoscopies for surveillance of recurrent urothelial bladder cancer (UCB) can be financially toxic for patients and lead to poor quality of life. CxMonitor is an mRNA-based home urine biomarker test that can potentially reduce the number of cystoscopies required during surveillance if indicating a low probability of cancer present. This study was to evaluate the performance of CxMonitor in predicting recurrence in UCB in a real-world setting. 

Methods:

From January 2017 to December 2022, patients scheduled for cystoscopy at the University of Southern California were offered CxBladder Monitor as part of their regular care. 119 patients completed CxMonitor samples, with 20 excluded due to sample rejection. All cystoscopy data were assessed at multiple timepoints to identify any recurrence, and the stage and grade were recorded. The comparative performance of the CxMonitor and cystoscopy was analyzed by calculating the sensitivity and specificity for any recurrence during the 12-month surveillance period. Additionally, negative predictive value (NPV) and positive predictive value (PPV) were calculated for comparative purposes.

Results:

Overall, 99 patients were included in our analysis. Patient demographics can be seen in Table 1. There was a significant difference (p= 0.03) in the age of patients tested positive at the time of CxM. No other significant differences including race, smoking status, presence of hematuria, or prior intravesical therapy. At the time of diagnosis, 70% of patients found to be positive were found to have high grade tumors with the largest portion of patients with pTa staging. Pathological staging and recurrence data can be seen in detail on Table 2. The sensitivity and specificity of CxMonitor at 12-months was 90% and 44.1% respectively. The NPV at 3, 6, 9, and 12 months was 100%, 88.9%, 90%, and 93.8% respectively.

Conclusion:

The at-home CxM urine assay retains its high sensitivity and NPV in a real world examination of patients as part of standard of care. Our study reinforces the high NPV of CxMonitor at 12 months, potentially allowing for less invasive methods of monitoring for recurrence in UCB. More larger and multi-institutional studies are required to better assess the effectiveness of CxMonitor as a method for reducing the need for frequent cystoscopies.

Funding: N/A