Introduction: Bladder cancer (BC) has a variable clinical course. With frequent recurrence, cystoscopy and urine cytology are routinely employed during follow-up of patients with a history of non-muscle invasive bladder cancer (NMIBC). Although there are multiple FDA approved urine-based tests for BC detection and surveillance, diagnostic accuracy of these urine-based assays is still suboptimal. Here, we compare the diagnostic value of urine cytology and a newly developed urine-based DNA methylation test for surveillance of NMIBC. Methods: We included patients undergoing blue-light surveillance cystoscopy for NMIBC between February 2019 and September 2021. Urine samples were collected at each surveillance cystoscopy. Samples were analyzed with Bladder CARE, a urine-based assay that measures methylation levels of 3 bladder cancer specific biomarkers (TRNA-Cys, SIM2, and NKX1-1) and two internal control loci using methylation-sensitive restriction enzymes coupled with qPCR. Results are reported as Bladder CARE Index (BCI) score and categorized as “positive” (BCI>5), “high risk” (2.5 Results: A total of 503 samples were collected from 159 patients (median age of 73, 77% male). 103 biopsies were performed during surveillance cystoscopies, of which 26 (25%) showed evidence of cancer recurrence. BCI was positive in all but four (high-risk) of the positive biopsies. While cytology was atypical in 7(27%) and highly suspicious in 2(8%) of the positive biopsies. Among 77 negative biopsies, BCI was positive in 27 samples from 20 patients, of whom 8 patients developed recurrence detected during subsequent follow ups. Cytology was only atypical in 2/8 patients. Three patients had normal cystoscopies and positive BCIs who developed upper tract urothelial carcinoma later. BCI was able to predict the recurrence within a median of 7 months prior. The Receiver Operating Characteristic (ROC) curve using the BCI values demonstrated the sensitivity, specificity, positive predictive values, and negative predictive value of 93%, 65%, 73.5%, and 89.5%, respectively. Conclusions: Urine cytology had low sensitivity and PPV for urothelial carcinoma in this cohort. Our findings demonstrated the necessity of more accurate urine biomarkers in the surveillance of NMIBC patients. Our preliminary results showed that Bladder CARE has high sensitivity and can potentially predict future recurrences. SOURCE OF Funding: Zymo Research Corp
