Preoperative assessment of the depth of early gastric cancer invasion by transabdominal ultrasound sonography (TUS): a comparison with endoscopic ultrasound sonography (EUS).

BACKGROUND/AIMS: Transabdominal ultrasound sonography (TUS) is considered a useful diagnostic tool ascertaining depth of cancer invasion, but there are few detailed studies on its accuracy in preoperative estimations of depth of invasion in early gastric cancer (mucosal and submucosal cancer). We retrospectively analyzed the clinical efficacy of preoperative evaluation by TUS in early gastric cancer in comparison with endoscopic ultrasound sonography (EUS).

METHODOLOGY: A total of 101 patients preoperatively diagnosed as early gastric cancer were enrolled in the current study. Patients were given 300cc of water subsequent to administration of an anti-peristaltic agent to facilitate filling the gastric lesion with water and TUS was performed. All patients were preoperatively examined by both EUS and TUS.

RESULTS: The depth accuracy in mucosal cancer was 59% with EUS and 66% with TUS. When submucosal cancers were subdivided into shallow and deep submucosal cancers, the depth of mucosal and shallow-submucosal (SM1) cancers were correctly assessed 80% and 78% by EUS and TUS, respectively. Accuracy increased by 12% in mucosal cancer by combining EUS and TUS diagnoses.

CONCLUSIONS: The diagnostic value of TUS is comparable to that of EUS in assessing depth of invasion of early gastric cancer, however, TUS had a possibility of misdiagnosing the depth of tumors located at the anterior wall. To ensure an accurate estimation of the depth of tumor invasion, it is recommended that TUS and EUS be done simultaneously.