A novel endoscopic classification system to determine the invasion depth of early esophageal cancer

Objective To develop a novel endoscopic classification system to determine the invasion depth of early esophageal cancer. Methods The esophageal lesion was endoscopically stained with Lugol＇s iodine first, then methylene blue. According to the growth pattern, height and cup depth under endoscope, the lesions were classified into 5 types, including surface diffusion growth, intra-lumen growth, intra-wall growth, bi-direction growth and mix growth types. The lesions were then removed by endoscopic mucosa resection or surgery, the precise invasion depth of the lesion was determined pathologically and the results were compared with the endoscopy classification. Results The data of 44 cases of esophageal mucosal cancer and 34 cases of esophageal sub-mucosal cancer were included. With the criteria of mucosal cancer as surface diffusion growth, intra-lumen growth 〈 5mm, bi-direction growth 〈 2mm and intra-wall growth 〈 0. 5 mm, the diagnostic specificity was 89. 1% （41/46） and sensitivity was 93.2% （41/44）. With the criteria of submucosal cancer as intra-lumen growth t〉5 mm, bi-direction growth ≥2mm, intra-wall growth /〉0. 5 mm and mix growth type, the diagnostic specificity was 90. 6% （29/32） and sensitivity was 85.3% （29/34）. The overall diagnostic accuracy in differentiating esophageal mucosal cancer from esophageal submucosal cancer by endoscopic classification was 89. 7% （70/78）. Conclusion This endoscopic classification system is effective in differentiating esophageal mucosal cancer from submucosal ones. Key words: Esophageal cancer;  Early diagnosis;  Endoscopy;  Invasion depth;  Classification