Endoscopic prediction of tumor invasion depth in early gastric cancer

Background Although conventional endoscopy is a good diagnostic tool to evaluate tumor depth (T staging) in early gastric cancer (EGC), its accuracy has not been determined and no consensus has been reached regarding standard endoscopic criteria. Objective To evaluate the diagnostic accuracy of endoscopic T staging and to identify the characteristic endoscopic features for mucosal (T1m) and submucosal (T1sm) tumors. Design Retrospective study. Patients A consecutive 2105 patients with EGC who underwent either surgical (n = 1624) or endoscopic (n = 481) resection. Intervention Endoscopic staging was performed by consensus of 2 endoscopists based on the characteristic endoscopic criteria of T1m (smooth surface protrusion or depression, slight marginal elevation, and the smooth tapering of converging folds) and T1sm (irregular surface, marked marginal elevation, and clubbing/abrupt cutting/fusion of converging folds). The endoscopic staging was compared with the pathologic staging of the resected specimen. Results The overall accuracy of endoscopic staging was 78.0% (1642/2105). The sensitivity, specificity, and positive and negative predictive values of T1m endoscopic staging were 85.5%, 73.9%, 82.0%, and 78.5%, whereas those for T1sm were 72.6%, 81.9%, 71.9%, and 82.4%, respectively. Limitations Retrospective study. Endoscopic predictions for T1sm tumors were correct in only 72% of cases. Conclusions Conventional endoscopy was found to provide reliable accuracy for T staging in EGC and may be an effective method for assessing penetration depth. A detailed endoscopic evaluation regarding tumor base, margin, and converging folds may provide useful information to determine tumor depth and to select the optimal therapeutic strategy, particularly for endoscopic resection.