Comparison of endoscopic ultrasonography and conventional endoscopy for prediction of tumor depth in superficial non-ampullary duodenal epithelial tumors

Background and study aim: The utility of endoscopic ultrasonography (EUS) in predicting tumor depth among superficial non-ampullary duodenal epithelial tumors (SNADET) is unclear. The aim was to compare EUS with conventional endoscopy (CE) for the evaluation of tumor invasion of SNADETs. 
Patients and methods: A retrospective analysis was performed on consecutive 176 lesions/171 patients with duodenal dysplasia or adenocarcinoma with invasion up to submucosa who underwent both CE and EUS before endoscopic (n=134) or surgical (n=42) treatment. The diagnostic performance of each test was compared with the final histology.
Results: The sensitivity and accuracy of estimating the depth were higher for CE compared to that of EUS (99.4% vs 89.0%, P=0.000 and 97.7% vs 87.5%, P=0.000, respectively). Univariate analysis of endoscopic factors revealed that tumor diameter, red color, SMT-like appearance and low echogenicity were factors related to advanced histology. Multivariate analysis revealed that the presence of SMT-like appearance based on CE was an independent factor to predict submucosal invasion (P=0.021). Gross morphology of combined type was associated to EUS accuracy (P=0.029). Among 3 cases in which EUS overestimated the tumor depth, carcinoma extension in submucosal Brunner’s gland or non-tumorous submucosal cystic dilation were observed.
Conclusion: EUS may not be necessary routinely, and CE may be sufficient for determining the optimal therapeutic strategy for SNADETs.