Background: The 2010 Japanese Gastric Cancer Association guidelines for the treatment of submucosal invasive gastric cancer (SM-GC) specify size 30 mm or less, differentiated-dominant histology, lack of vessel involvement, and submucosal invasion of less than 500 μm (SM1) as expanded criteria for curative endoscopic resection. Our purpose in this study was to confirm the validity of the expanded indications for curative endoscopic submucosal dissection (ESD) of SM-GC.
Methods: The study subjects were 173 patients with SM-GC resected by ESD at Hiroshima University Hospital between April 2002 and September 2010, including 99 patients for whom 3-plus years' follow-up information was available. Post-ESD outcomes were compared between cases of SM1-GC that met the expanded ESD criteria, those that did not, and SM2-GC cases.
Results: Complete resection was achieved for 93.2% of the SM1-GCs that met the expanded criteria. There was neither metastasis to lymph nodes or other organs nor local recurrence among the SM1-GCs. Disease-specific survival did not differ significantly between patients that were simply followed up after ESD and those that were treated by additional surgical resection.
Conclusions: Our outcome data support the clinical validity of ESD without additional surgical resection for SM1-GCs that meet the expanded criteria.