Is endoscopic ultrasonography indispensable in assessing the appropriateness of endoscopic resection for gastric cancer?

Background and Study Aims: Endoscopic resection is increasingly being used in the treatment of early gastric cancer. The aim of the present study was to investigate the accuracy of pre-therapeutic staging techniques for assessing the appropriateness of endoscopic resection. Patients and Methods: Both endoscopy and endosonography were carried out at our institution in the treatment of 234 early gastric cancers, with histological confirmation of malignancy following surgical resection (137 lesions) or endoscopic resection (97 lesions). The accuracy in detecting intramucosal cancer with each of the diagnostic procedures was assessed. Results: The accuracy rates for detecting intramucosal cancer using endoscopy and endosonography were calculated as 84% (197 of 234) and 78% (182 of 234), respectively. The accuracy tended to be lower in lesions located in the upper third of the stomach, in those measuring 2 cm or more in diameter, and in those with an undifferentiated histology with ulcer fibrosis. However, there were no significant differences in the accuracy rates between endoscopy and endosonography. Precise staging was achieved by endoscopy alone in 103 of 109 differentiated adenocarcinomas without ulcer fibrosis, where the lesions measured less than 2 cm in diameter. Conclusions: Endoscopic resection is indicated in intramucosal gastric cancer lesions showing differentiated histology, no ulcer fibrosis and a diameter of less than 2 cm. EUS may additionally be used for further evaluation in these patients.