Optimal selection of endoscopic resection in patients with esophageal squamous cell carcinoma: endoscopic mucosal resection versus endoscopic submucosal dissection according to lesion size.

En bloc resection is essential for accurate pathological evaluation in patients with superficial esophageal squamous cell carcinoma (SESCC). This retrospective study aimed to clarify optimal treatment selection of endoscopic resection according to lesion size. A total of 760 patients underwent endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) between January 2011 and December 2015. Among them, this retrospective study included 196 solitary index SESCC lesions ≤20 mm, with the deepest invasion to the mucosa or superficial submucosa endoscopically. The lesions were classified according to size measured via endoscopy as follows; group A: lesions ≤10 mm, group B: lesions ≥11 mm but ≤15 mm, and group C: lesions ≥16 mm but ≤20 mm. The short- and long-term outcomes were investigated for EMR and ESD subgroups. In patients undergoing EMR and ESD, en bloc resection rates for group A and B were not different (98.8 vs. 100%, 93.3 vs. 100%, respectively). However, the en bloc resection rate was significantly lower in EMR than that in ESD for group C (64.3 vs. 100%, P < 0.001). Furthermore, the use of adjunctive ablative therapy rate was significantly higher in EMR than that in ESD in group C (35.7 vs. 0%, P < 0.001). The 5-year cumulative local recurrence rate of group C was significantly higher than that of group A + B after EMR (P < 0.01). EMR was an adequate treatment for SESCC lesions ≤15 mm. On the other hand, ESD could be necessary to achieve en bloc resection for lesions ≥16 mm to avoid local recurrence.