Acetic acid chromoendoscopy for the diagnosis of early neoplasia and specialized intestinal metaplasia in Barrett's esophagus: a meta-analysis

Background and Aims: Barrett's esophagus (BE) surveillance with random biopsies is time-consuming, invasive, and can lead to sampling error. Acetic acid chromoendoscopy (AAC) with targeted biopsies has been proposed as an effective alternative. The aim of this study was to assess the diagnostic accuracy of AAC for the detection of early neoplasia (high-grade dysplasia [HGD] or early cancer [EC]) and specialized intestinal metaplasia (SIM) in patients with BE. Methods: We performed a meta-analysis of all primary studies that compared AAC-based diagnoses (index test) with histopathology as the reference standard. The data were extracted on a per-patient, per-area, and perprocedure basis whenever available. Results: Thirteen prospective studies met the inclusion criteria. For the diagnosis of HGD/EC, the pooled sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR-) for all included studies (9 studies, 1379 patients) were 0.92 (95% confidence interval [CI], 0.83-0.97), 0.96 (95% CI, 0.85-0.99), 25.0 (95% CI, 5.9-105.3), and 0.08 (95% CI, 0.04-0.18), respectively. Results were not significantly different when considering only studies with a per-patient analysis. For the characterization of SIM, the pooled sensitivity, specificity, LR+, and LR- for all the included studies (8 studies, 516 patients) were 0.96 (95% CI, 0.83-0.99), 0.69 (95% CI, 0.54-0.81), 3.0 (95% CI, 2.0-4.7), and 0.06 (95% CI, 0.01-0.26), respectively. No significant sources of heterogeneity were identified on subgroup analysis. Conclusion: AAC has an overall high diagnostic accuracy for detecting HGD/EC in patients with BE. For SIM characterization, AAC sensitivity is very high but has poor specificity, suggesting that histological confirmation is necessary when AAC is positive.