Factors associated with incomplete gastric endoscopic submucosal dissection due to misdiagnosis

Background and study aims: Endoscopic submucosal dissection (ESD) is widely accepted for treating early gastric cancer (EGC); however, there can be cases of incomplete resection due to not only technical problems, but also misdiagnosis. Our aim was to identify factors associated with incomplete gastric ESD due to misdiagnosis. Patients and methods: A total of 2,268 patients with solitary EGCs at initial onset underwent ESD with curative intent at our hospital from 1999 to 2008. We retrospectively assessed the clinicopathological factors by comparing the two groups of incomplete ESD cases due to misdiagnosis (cases with a positive lateral margins [LM] [Group A] or those with a positive vertical margins [VM] [Group B]) with complete ESD cases using multivariable analysis. Results: Complete ESD was achieved in 2,097 patients. The 171 patients with incomplete ESDs were divided into 109 with a positive LM and 80 with a positive VM (overlapped). Except 49 cases with a positive LM due to technical problems, a positive LM due to misdiagnosis was identified in 60 cases (Group A). Excluding 32 cases with a positive VM due to technical problems, a positive VM due to misdiagnosis was found in 48 cases (Group B). Significant independent factors (odds ratios [OR]; 95 % confidence intervals [CI]) for each group were as follows: Group A: size > 20 mm (5.4; 3.0 – 9.9), undifferentiated-type (4.1; 1.8 – 9.0), submucosal invasion (2.0; 1.1 – 3.4) and location of upper/middle (1.9; 1.0 – 3.6); Group B: size > 20 mm (3.0; 1.6 – 5.5), undifferentiated-type (3.0; 1.1 – 8.0) and location of upper/middle (2.4; 1.2 – 4.8). Conclusions: Endoscopists must be aware of these factors associated with incomplete gastric ESD due to misdiagnosis to further decrease their incidence.