Diagnostic Performance of Confocal Laser Endomicroscopy for the Detection of Bladder Cancer: Systematic Review and Meta-Analysis

Objective: To systematically evaluate the diagnostic efficacy of confocal laser endomicroscopy (CLE) in detection of bladder cancer. Methods: A systematic literature search on CLE in diagnosing bladder cancer in PubMed, Embase, and the Cochrane Library databases was performed. A bivariate meta-regression model was used for meta-analysis to evaluate the pooled diagnostic value of CLE. Results: A total of 5 eligible studies involving 302 lesions were available for this meta-analysis. In a per-lesion analysis, pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver-operating curve (SROC) area under the curve (AUC) of CLE for malignant lesions were 0.90 (95% confidence interval [CI]: 0.85–0.94), 0.72 (95% CI: 0.59–0.82), 3.20 (95% CI: 2.14–4.79), 0.14 (95% CI: 0.09–0.21), 23.27 (95% CI: 11.71–46.25), and 0.91 (95% CI: 0.89–0.94), respectively. For low-grade urothelial carcinomas, pooled sensitivity, specificity, PLR, NLR, DOR, and AUC for CLE were 0.72 (95% CI: 0.57–0.84), 0.87 (95% CI: 0.77–0.93), 5.48 (95% CI: 3.12–9.62), 0.32 (95% CI: 0.20–0.50), 17.19 (95% CI: 8.01–36.89), and 0.85 (95% CI: 0.82–0.88), respectively. For high-grade urothelial carcinomas, pooled sensitivity, specificity, PLR, NLR, DOR, and AUC for CLE were 0.82 (95% CI: 0.62–0.92), 0.84 (95% CI: 0.73–0.91), 4.96 (95% CI: 2.58–9.54), 0.22 (95% CI: 0.09–0.52), 22.49 (95% CI: 5.33–94.85), and 0.89 (95% CI: 0.86–0.91), respectively. Conclusion: CLE is a promising endoscopy technique for real-time tumor grading of bladder cancer.