2401P - Detection of molecular recurrence in early-stage bladder cancer patients using a urinary tumor DNA assay after transurethral resection of bladder tumor (TURBT)

Background

Transurethral resection of bladder tumor (TURBT) is the primary treatment for early-stage bladder cancer, and early detection of tumor recurrence is vital for improving patient outcome. Non-invasive and reliable methods for monitoring molecular changes in urine represent a promising avenue to facilitate timely intervention and effective disease management.

Methods

In this ongoing prospective study, 95 patients with early-stage bladder cancer were recruited, whose urine samples were collected prior to TURBT. Afterward, patients were advised to provide urine samples during follow-up visits. PredicineCARE, a targeted next-generation sequencing (NGS) liquid biopsy assay, was employed to identify somatic alterations in urinary tumor DNA (utDNA). Based on these alterations, the tumor fraction was assessed to identify molecular recurrence in the patients.

Results

Out of the 95 patients, 48 were diagnosed with non-muscle invasive bladder cancer (NMIBC) and 47 with muscle invasive bladder cancer (MIBC). The genes that showed the most frequent variations in NMIBC patients were TP53 (54%), TERT (46%), FGFR3 (31%), ERCC2 (31%), ARID1A (31%), and CDKN2A (31%). Meanwhile, in MIBC, the most frequently varied genes were TP53 (74%), TERT (47%), PIK3CA (32%), and KDM6A (32%). 38.5% of NMIBC patients and 26.3% of MIBC patients harbored FGFR2/3 variations, suggesting that they could potentially benefit from FGFR inhibitors. Among the 29 patients with follow-up data, longitudinal urine samples of 12 patients (2 NMIBC, 10 MIBC) were tested. Nine patients (2 NMIBC, 7 MIBC) showed a significant decrease in tumor fraction, one (MIBC) remained stable, and two patients (MIBC) exhibited increasing tumor fraction, indicating molecular recurrence of the disease.

Conclusions

The results of this study confirm the validity of utilizing a utDNA assay to detect molecular recurrence in early-stage bladder cancer patients who have undergone TURBT treatment, which can be instrumental in facilitating early detection of tumor recurrence and guiding treatment decisions. These findings underscore the enormous potential of urine-based NGS assays for urothelial cancer detection and disease surveillance.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.