Endoscopic resection of early gastric cancer.

The purpose of this review is to examine recent advances in the techniques and technologies of endoscopic resection of early gastric cancer (EGC). Endoscopic mucosal resection (EMR) of EGC, with negligible risk of lymph node metastasis, is a standard technique in Japan and is increasingly becoming accepted and regularly used in Western countries. EMR is a minimally invasive technique which is safe, convenient, and efficacious; however, it is insufficient when treating larger lesions. The evidence suggests that difficulties with the correct assessment of depth of tumor invasion lead to an increase in local recurrence with standard EMR when lesions are larger than 15 mm. A major factor contributing to this increase in local recurrence relates to lesions being excised piecemeal due to the technical limitations of standard EMR. A new development in endoscopic techniques is to dissect directly along the submucosal layer -- a procedure called endoscopic submucosal dissection (ESD). This allows the en-bloc resection of larger lesions. ESD is not necessarily limited by lesion size and it is predicted to replace conventional surgery in dealing with certain stages of ECG. However, it still has a higher complication rate when compared to standard EMR, and it requires high levels of endoscopic skill and experience. Endoscopic techniques, indications, pathological assessment, and methods of endoscopic resection of EGC need to be established for carrying out appropriate treatment and for the collation of long-term outcome data.