Endoscopic submucosal dissection for superficial Barrett's esophageal cancer in the Japanese state and perspective.

The incidence of Barrett's esophageal cancer is one of the most rapidly increasing among all cancers in the West, and it is also expected to increase in Japan. The optimal treatment for early Barrett's esophageal cancer remains controversial. En bloc esophagectomy with regional lymph node dissection has been considered the standard therapy. Endoscopic therapies are currently being evaluated as alternatives to esophagectomy because they can provide the least postoperative morbidity and the best quality of life. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) allow for removal of visible lesions and histopathologic review of resected tissue, which help in diagnostic staging of the disease. EMR is limited with respect to resection size, and large lesions must be resected in several fragments. Piecemeal resection of lesions is associated with high local recurrence rates, probably because of minor remnants of neoplastic tissue being left in situ. ESD provides larger specimens than does EMR in patients with early Barrett's neoplasia. This in turn allows for more precise histological analysis and higher en bloc and curative resection rates, potentially reducing the incidence of recurrence. Detailed endoscopic examination to determine the invasion depth and spread of Barrett's esophageal cancer is essential before ESD. The initial inspection is usually conducted with white-light imaging followed by narrow-band imaging. The ESD procedure is similar to that for lesions in other parts of the gastrointestinal tract. However, the narrow space of the esophagogastric junction and contraction of the lower esophageal sphincter sometimes disturb the visual field and endoscopic control. Skilled endoscope handling, sometimes including retroflexion, is required during ESD for Barrett's esophageal cancer. Previous reports have shown that ESD achieves en bloc resection in >80% of lesions. Although promising short-term results are reported, a long-term, large-scale study is required for better understanding of ESD for Barrett's esophageal cancer.