Clinicopathologic factors influence accurate endosonographic assessment for early gastric cancer

Background and Objective: EUS has become a valuable tool for the selection of patients who are suitable for EMR of early gastric cancer (EGC). The aim of this study was to evaluate the various clinicopathologic factors affecting the diagnostic accuracy of EUS in EGC. Design and Setting: A retrospective, single-center study. Patients: A total of 206 patients suspected of EGC endoscopically who underwent EUS examination and curative treatment for EGC at Severance Hospital, Seoul, Korea, from October 2001 to May 2005 were included. Interventions: We reviewed the medical records of 206 patients and compared preoperative EUS staging with final histopathologic staging of the resected specimen according to the clinicopathologic parameters. Main Outcome Measurements and Results: The diagnostic accuracy of EUS for predicting tumor invasion depth was significantly affected by the histopathologic differentiation and the size of tumor. The differentiated cell types were associated with higher diagnostic accuracy in predicting the tumor invasion. Lesions located in the mid one third of the stomach larger than 3 cm had significantly higher probability of overstaging. Poorly differentiated histologic diagnosis had a significantly higher probability of understaging. There was no significant factor associated with the endosonographic prediction of lymph node metastasis. Conclusions: EGC with undifferentiated histopathologic features or large tumor size is more frequently associated with an incorrect diagnosis in tumor invasion depth by EUS. EGC with a size larger than 3 cm and poorly differentiated histologic diagnosis should be cautiously considered in the decision on treatment modality by pretreatment EUS staging.