Endoscopic resection for early gastric cancer: The current controversies

Gastric cancer remained second commonest cancer worldwide. The diagnosis of early gastric cancer (EGC) is increasing in Japan and South Korea resulting in better oncological outcomes. Endoscopic resection (ER) is safe and effective treatment for EGC with minimal risk of lymph node metastasis. The oncological clearance of ER for EGC in expanded criteria remains controversial. Several retrospective studies showed that endoscopic submucosal dissection (ESD) achieved minimal local recurrence and excellent survival for EGC in expanded indications. With an increasing trend of cancer occuring in the aging population, ER will play a major role in treatment of EGC among elderly who usually have multiple comorbidities. Salvage gastrectomy is generally recommended for those with non-curative ESD, while further researches should be conducted to refine the risks of nodal metastasis for various submucosal EGCs. Endoscopic surveillance is recommended for long term follow-up of patients after curative ESD as the risk of metachronous cancer is significant. Eradication of Helicobacter pylori is generally recommended for EGC treated by ER with a view to reduce the risk of metachronous tumor.

Peroral Endoscopic Myotomy for Treating Achalasia and Esophageal Motility Disorders

Peroral endoscopic myotomy (POEM) is the application of esophageal myotomy to the concept of natural orifice transluminal surgery (NOTES) by utilizing a submucosal tunneling method. Since the first case of POEM was performed for treating achalasia in Japan in 2008, this procedure is being more widely used by many skillful endosopists all over the world. Currently, POEM is a spotlighted, emerging treatment option for achalasia, and the indications for POEM are expanding to include long-standing, sigmoid shaped esophagus in achalasia, even previously failed endoscopic treatment or surgical myotomy, and other spastic esophageal motility disorders. Accumulating data about POEM demonstrate excellent short-term outcomes with minimal risk of major adverse events, and some existing long-term data show the efficacy of POEM to be long lasting. In this review article, we review the technical details and clinical outcomes of POEM, and discuss some considerations of POEM in special situations.