Long-term outcomes of endoscopic submucosal dissection for early gastric cancer: a multicenter collaborative study

Objective The indications for endoscopic submucosal dissection (ESD) in patients with early gastric cancer (EGC) have been expanded. However, the long-term outcomes of ESD remain unclear. We retrospectively investigated the long-term outcomes of ESD in patients with EGC. Methods We retrospectively studied patients with EGC who underwent ESD at 11 institutions between January 2003 and December 2010. A total of 6456 patients (7979 lesions) who met the absolute indications for ESD and 4202 patients (5781 lesions) who met the expanded indications for ESD were studied. Clinicopathological features, clinical course, and outcomes were studied in 67 patients in whom local recurrence or metastatic recurrence was diagnosed as of March 31, 2014. The median follow-up period was 56 months. Results Local recurrence was diagnosed in 14 patients (0.22%) who met the absolute indications and 53 patients (1.26%) who met the expanded indications. The rate of local recurrence was significantly higher in patients with expanded-indication lesions (p < 0.05). As additional treatment for recurrence, most patients received endoscopic treatment. Metastatic recurrence did not develop in any patient with absolute-indication lesions, but was diagnosed in 6 patients (0.14%) with expanded-indication lesions (p < 0.05). The histological type was undifferentiated mixed type in half the patients. Three patients died of primary gastric cancer. Conclusions ESD for expanded-indication lesions of EGC is considered an effective therapy associated with an extremely low rate of metastatic recurrence on long-term follow-up. However, fully informed consent concerning the risk of metastatic recurrence should be obtained before ESD, and close postoperative follow-up is essential.