Published online Apr 14, 2014. doi: 10.3748/wjg.v20.i14.3938
Revised: January 18, 2014
Accepted: February 17, 2014
Published online: April 14, 2014
Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients’ desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.
Core tip: Endoscopic submucosal dissection (ESD) for intramucosal undifferentiated (UD) type early gastric cancer (EGC) without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. In contrast, the controversial results about the safety of ESD for UD-EGC fulfilling the criteria have been reported and a little is known about the long-term outcomes. Therefore, in this review, we focused on the safety and therapeutic efficacy of ESD for UD-EGC with reference to risks for lymph node metastasis within the proposed criteria as well as the short-term and long-term outcomes of ESD for UD-EGC.