Novel Endoscopic Criteria for Predicting Tumor Invasion Depth in Superficial Esophageal Squamous Carcinoma

BACKGROUND: Accurate prediction of tumor invasion depth in superficial esophageal squamous carcinoma (SESC) is essential for deciding the appropriate treatment strategy. We proposed novel endoscopic criteria to differentiate between mucosal and submucosal esophageal cancers and to evaluate the diagnostic accuracy and usefulness of the criteria. METHODS: A total of 352 patients who underwent endoscopic or surgical resection for SESC between 1991 and 2010 were included. First, the novel endoscopic criteria were created based on the endoscopic features of 60 randomly selected patients as follows: for T1m cancers, I. flat or slightly elevated or depressed lesion with smooth/even surface of any size, II. slightly elevated lesion of ≤ 1 cm with granular or uneven surface, III. hyperemic flat lesion of ≤ 3 cm with granular or uneven surface, IV. slightly depressed lesion of ≤ 2 cm with uneven surface and for T1sm cancers, I. irregularly (unevenly) nodular or protruded lesion of any size, II. slightly elevated lesion of > 1 cm with granular or uneven surface, III. hyperemic flat lesion of > 3 cm with granular or uneven surface, IV. irregularly (unevenly) depressed lesion of > 2 cm, and V. ulcerative lesion of any size. Next, the endoscopic findings of the remaining 292 patients were reviewed according to the criteria. RESULTS: The accuracy of novel endoscopic criteria was 79.5% (232/292). The sensitivity and specificity of mucosal cancers were 78.4% and 81.0%, respectively, whereas those for submucosal cancers were 81.0% and 78.4%, respectively. The accuracy for mucosal cancers was high (97.3%, 72/74) when the lesions were flat or slightly elevated/depressed with smooth/even surface regardless of size, whereas that for submucosal cancers was high (85.7%, 18/21) when the lesions were irregular/nodular protrusions regardless of size. In multivariate analysis, macroscopic type IIb lesion was identified as an independent factor affecting accuracy (P < 0.05). The difference in recurrence-free survival rates between endoscopically mucosal and submucosal cancers was significant (P = 0.026). CONCLUSION: The novel endoscopic criteria appear to be accurate and useful in predicting invasion depth in SESC. Our criteria might help not only to decide the treatment strategy between surgery and endoscopic resection but also to predict the outcomes of SESC.