Abstract
BACKGROUND: Non-muscle-invasive bladder cancer (NMIBC) has a high recurrence rate, necessitating rigorous surveillance primarily reliant on invasive cystoscopy. While urine cytology offers high specificity, its sensitivity for low-grade tumors is unacceptably low. CellDetect is a novel histochemical staining test based on differential metabolic activity between normal and malignant cells, which is often referred to as the Warburg effect. This study aimed to evaluate its real-world diagnostic performance for detecting NMIBC recurrence. METHODS: This retrospective cohort study included 243 patients under surveillance after transurethral resection of bladder tumor (TURBT). All patients underwent both the CellDetect test and cystoscopy within 24 months post-operatively. Using cystoscopy and histopathology as the reference standard, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CellDetect were evaluated. Subgroup analyses were performed based on tumor grade, stage, and European Organization for Research and Treatment of Cancer (EORTC) risk category. RESULTS: Among the 52 patients (21.4%) with histologically confirmed recurrence, the overall sensitivity of the CellDetect test was 76.9%, specificity was 78.0%, PPV was 52.6%, NPV was 91.2%, and overall accuracy was 77.8%. Sensitivity was significantly higher for high-grade (HG) tumors (93.8%) than for low-grade (LG) tumors (69.4%). In the high-risk EORTC subgroup, sensitivity was 88.9% and NPV was 95.2%. Furthermore, among 18 patients with “discordant” findings (positive CellDetect/ negative cystoscopy), 6 (33.3%) were subsequently diagnosed with recurrence upon random biopsy. CONCLUSION: In this retrospective analysis, the CellDetect test demonstrated encouraging diagnostic performance in the post-TURBT surveillance setting, particularly its high NPV and sensitivity for HG tumors. “Discordant” results may hold predictive value for imminent recurrence. Further prospective validation is warranted. CellDetect represents a potential tool for developing a more personalized, risk-adapted, and patient-friendly follow-up strategy for NMIBC.