Confocal Laser Endomicroscopy for Bladder Cancer Detection: Where Do We Stand?

Abstract

Introduction: Confocal laser endomicroscopy (CLE) is a relatively new technology that allows for a real-time in situ microscopic characterization of tissue lesions, being able to discriminate between low- and high-grade ones. After a first period of slow diffusion caused by technological limitations and elevated costs, CLE applications are rapidly spreading in different branches of medicine, and there is mounting evidence of its advantages for the management of different tumors such as bladder cancer (BCa), from both a diagnostic and a clinical point of view. In this systematic review (SR), we evaluate the state-of-the-art CLE for BCa management. Material and methods: We performed an SR and quality assessment analysis of the current literature in this regard following the PRISMA guidelines. All data were independently verified by two different authors and discrepancies were solved by a third author. Moreover, a quality-assessment analysis according to QUADAS-2 criteria was performed to evaluate the studies selected for SR. Results: A total of 158 articles were retrieved; of which 79 were rejected and 38 were removed as duplicates. After article selection, seven prospective studies were assessed for data extraction. These accounted for 214 patients overall, with a correspondence rate between CLE and histopathological examination ranging from 54.6 to 93.6%. Regarding quality assessment, three out five prospective studies have at least a high risk of bias in one QUADAS-2 domain, whereas the applicability always has a low risk of bias. Conclusion: Despite actual technical limitations, the preliminary results of this appealing technology are encouraging and should prompt further investigations.