The Japanese Esophageal Society classification for prediction of superficial esophageal squamous cell neoplasia invasion depth: Validation in a Western population

Background: The Japan Esophageal Society proposed the JES microvessel classification to assess eligibility of early esophageal squamous cell neoplasia (ESCN) for endoscopic resection based on intrapapillary capillary loop assessment. We aimed to assess its diagnostic reproducibility and accuracy in Western ESCN patients. Methods: Intrapapillary capillary loops on endoscopic images of Western ESCN lesions (n = 113) collected between 2010 and 2022 were assessed by nine endoscopists, including three Japanese expert endoscopists, three Western expert endoscopists, and three residents-in-training, and graded according to the JES microvessel classification where microvessel type A corresponds with normality or low-grade intraepithelial neoplasia, and microvessel types B1, B2, and B3 correspond with high-grade intraepithelial neoplasia or invasion into the lamina propria, muscularis mucosae or superficial submucosa, and deep submucosa, respectively. Outcomes included overall accuracy in predicting ESCN invasion depth and interobserver agreement. Results: Good interobserver agreement was observed among expert endoscopists (Krippendorf's alpha 0.64, 95% CI 0.57–0.70), while agreement was moderate among residents-in-training (Krippendorf's alpha 0.58, 95% CI 0.52–0.72). Overall accuracy of the JES microvessel classification was 53% (95% CI 42–63), 52% (95% CI 41–62), and 44% (95% CI 34–55) for Japanese endoscopists, Western endoscopists, and residents-in-training, respectively. Sensitivity and specificity for vessel type A, B1, B2, and B3 across assessors were 0%–50% and 89%–100%, 55%–64% and 66%–77%, 42%–71% and 60%–76%, and 10%–24% and 92%–97%, respectively. Negative predictive value ranged between 80% and 85% for B3 vessels. Conclusion: Overall accuracy of the JES microvessel classification in Western ESCN patients is low, though absence of B3 vessels as assessed by experienced endoscopists may predict superficial ESCN amenable to endoscopic resection. Trial registry: www.trialregister.nl; NL8897 (6-9-2020).