A blind comparison of the effectiveness of endoscopic ultrasonography and endoscopy in staging early gastric cancer

Background/Aims-Endoscopic ultrasonography is expected to be useful for inv asion depth staging of early gastric cancer. A prospective blind study of t he staging characteristics of endoscopy and endoscopic ultrasonography for early gastric cancer was performed. Methods-Findings of endoscopy and endoscopic ultrasonography using a 20 MHz thin ultrasound probe were independently reviewed and the results of 52 ea rly gastric cancer lesions analysed. Results-The overall accuracy rates in invasion depth staging of early gastr ic cancer were 63% for endoscopy and 71% for endoscopic ultrasonography. No statistically significant differences were observed in overall accuracy. E ndoscopic ultrasonography tended to overstage, and lesions that were classi fied as mucosal cancer by endoscopic ultrasonography were very likely (95%) to be Limited to the mucosa on histological examination. All 16 lesions st aged as mucosal cancer independently but coincidentally by both methods wer e histologically limited to the mucosa. Conclusions-Endoscopic ultrasonography is expected to compensate for the un derstaging of lesions with submucosal invasion that are endoscopically stag ed as mucosal cancer.