Accuracy of high-frequency catheter-based endoscopic ultrasonography versus conventional endoscopy for the prediction of depth of tumor invasion in early gastric cancer

Purpose: The increasing performance of endoscopic resection for curative treatment of early gastric cancers (EGC) requires accurate tumor staging before therapy. Endoscopic ultrasonography (EUS) is the first choice imaging modality for determining the depth of invasion (T staging) of gastric cancer. The aim of the present study was to prospectively assess the accuracy of EUS for determining the depth of EGC compared to that of conventional endoscopy.

Methods: From September 2009 to May 2010, a total of 42 patients with a suspicion of early gastric cancer were prospectively enrolled in the study. EUS T staging was performed by an experienced endosonographer using 20MHz catheter probe. Conventional endoscopic T staging was carried out by one endoscopist independently of EUS assessment. Results of the both examinations were compared with histopathology of the endoscopically or surgically resected tumors.

Results: Overall accuracy of EUS and conventional endoscopy for T staging were 85.7% and 76.2%, respectively (P<0.021). For mucosal cancers, accuracy of EUS and conventional endoscopy was 94.6% and 81.1%, respectively. Tumor size, histologic differentiation, concomitant ulcer, groß morphology and location of tumor didn't influenced accuracy of EUS.

Conclusions: Accuracy of high-frequency-based EUS was superior to that of conventional endoscopy for the prediction of depth of tumor invasion in EGC. EUS is a more accurate predictior for T staging of EGC which is planned to endoscopic resection.