Diagnostic accuracy of Raman spectroscopy for the diagnosis of bladder cancer: A systematic review and meta-analysis

Introduction: Although several studies have been conducted to evaluate the feasibility of Raman spectroscopy (RS) for the diagnosis of bladder cancer (BCa), it is difficult to use RS in real clinical settings based on the current limited evidence. Therefore, we performed a systematic review and meta-analysis to assess the diagnostic accuracy of RS in BCa. Materials and Methods: Comprehensive literature searches were performed in the PubMed/Medline, Embase, and Cochrane Library databases up to March 2019. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, this study included reports according to the participant, intervention, comparator, outcomes, and study design approach. The methodological quality of the included studies was evaluated according to questionnaires and criteria suggested by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The quantitative outcomes included diagnostic accuracy (sensitivity and specificity). Results: Fifteen studies were included for qualitative analysis and four studies (BCa cases, n = 139; control cases n = 107) were included in this analysis by screening the full text of the remaining articles based on the inclusion and exclusion criteria through a systematic review. The pooled sensitivity and specificity of RS were 0.91 (95% confidence interval [CI]: 0.85-0.95) and 0.93 (95% CI: 0.86-0.97), respectively. The among-study heterogeneity was statistically significant in the specificity results (Cochran Q statistic, P = 0.015; I2 statistic, 71.3%) but not in the sensitivity results (Cochran Q statistic, P = 0.189; I2 statistic, 37.2%). Conclusions: RS showed the potential to be an efficient tool with high accuracy for detecting malignant bladder lesions. More studies with in vivo real-time settings are warranted to validate our results.