Endoscopic ultrasonography and endoscopy for staging depth of invasion in early gastric cancer: a pilot study

Background We compared the accuracy of endoscopic ultrasonography (EUS) for staging depth of invasion of early gastric cancer with that of conventional endoscopy. Patients and methods: We assessed the depth of invasion of 108 lesions (104 patients) using EUS with a thin 20 MHz probe and compared the results with those of conventional endoscopy and of histologic examination of endoscopically or surgically resected specimens. Results: The overall accuracy rates for staging depth of invasion for conventional endoscopy and EUS were 72.2% and 64.8%, respectively. Lesions that were classified as limited to the mucosa on both conventional endoscopy and EUS were very likely (92.2%) to be limited to the mucosa on histologic examination. The rates for understaging and overstaging were 16.7% and 11.1%, respectively, for conventional endoscopy; and 7.4% and 24.1%, respectively, for EUS. The highest rate for understaging based on conventional endoscopy occurred for lesions in the gastric body (including cardia, 23.9%). Conclusions: EUS appears to be useful in combination with conventional endoscopy for staging depth of invasion of early gastric cancer. In particular, the two techniques in tandem may accurately predict that a lesion is limited to the mucosa, and EUS may be useful to overcome the potential for understaging by conventional endoscopy, particularly ii? the gastric body.