Evaluating diagnostic performance of urinary biomarkers in the surveillance of non-muscle invasive bladder carcinoma:

Purpose: Urinary biomarkers have been proposed to play an integral role in detecting recurrent non-muscle invasive bladder carcinoma (NMIBC). This review delineates the diagnostic accuracy of such biomarkers and management strategies in the event of discordance between biomarker findings and flexible cystoscopy, the current gold standard for NMIBC surveillance. Materials and methods: In accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement, literature searches were conducted across PubMed, Embase, Scopus, and CENTRAL (Cochrane Central Register of Controlled Trials), focusing on studies comparing urinary biomarkers to cystoscopy. The inclusion criteria were based on the PICOS (Patient Intervention Comparison Outcome Study type) model. The quality of included studies was assessed using the QUADAS-2 tool. Results: A total of 23 studies were included, encompassing 21 types of urinary biomarkers. The analysis revealed significant variability in diagnostic performance. Sensitivity ranged from 14.8% to 94.3%, specificity from 33.3% to 99.2%, positive predictive value from 9.9% to 100%, and negative predictive value from 35.3% to 98.8%. Heterogeneity was observed across studies, indicating variability in different biomarker performance. Genetic biomarkers demonstrated higher diagnostic accuracy compared to protein-based markers. However, their clinical utility needs further validation. Conclusions: Urinary biomarkers could complement, rather than replace cystoscopy, in the surveillance of NMIBC, potentially reducing the frequency of invasive procedures. In cases of discordance, an algorithm focusing on shared decision-making and tailored surveillance strategies can be undertaken. Large-scale multicentric studies are needed to confirm their efficacy and establish standardized clinical protocols.