Clinical outcomes of early gastric cancer patients after noncurative endoscopic submucosal dissection in a large consecutive patient series.

BACKGROUND: Clinical outcomes of early gastric cancer (EGC) patients after noncurative endoscopic submucosal dissection (ESD) have not been fully elucidated; we therefore aimed to clarify these outcomes.

METHODS: A total of 3058 consecutive patients with 3474 clinically diagnosed EGCs at initial onset underwent ESD with curative intent at our hospital between 1999 and 2010. We retrospectively assessed the following clinical outcomes of noncurative gastric ESD patients with a possible risk of lymph node (LN) metastasis by dividing patients into two groups with different treatment strategies (additional gastrectomy and simple follow-up): presence of LN metastasis at the time of gastrectomy, incidence of LN and distant metastases during the follow-up period, clinicopathological factors associated with metastasis, and 5-year disease-specific survival (DSS).

RESULTS: After exclusion of 75 noncurative ESD patients with only a positive horizontal margin, 569 noncurative ESD patients with a possible risk of LN metastasis were identified. Among the 356 patients undergoing additional gastrectomy, LN metastasis was identified in 18 patients. A positive vertical margin with submucosal invasion (odds ratio 3.6) and lymphovascular invasion (odds ratio 3.5) were significantly associated with LN metastasis. The 5-year DSS rate was 98.8 %. Among the 212 patients who underwent simple follow-up, LN and/or distant metastases were found in eight patients. In this group, lymphovascular invasion (hazard ratio 6.6) was significantly associated with metastasis with a 5-year DSS rate of 96.8 %.

CONCLUSIONS: Additional gastrectomy should be performed particularly in noncurative gastric ESD patients with lymphovascular invasion or a positive vertical margin with submucosal invasion.