Fig. 1

Flowchart of this study. a: 30, 23, 53, 55 and 35 patients were excluded due to inflammatory lesions, submucosal tumors, insufficient endoscopic or pathological records, protruding or excavated early ESCC, and advanced ESCC, respectively; b: enrolled patients were from four academic hospitals. Finally, 413, 307, 200 and 226 patients were enrolled from Zhongda Hospital Southeast University, First Affiliated Hospital of Nanjing Medical University, Huai’an First People’s Hospital affiliated to Nanjing Medical University and Taizhou People’s Hospital Affiliated to Nantong University; c: endoscopic resection or esophagectomy; d: 101 and 41 patients were recruited from Zhongda Hospital Southeast University and Taizhou People’s Hospital Affiliated to Nantong University, respectively. WLI white-light imaging, SESCC superficial esophageal squamous cell carcinoma