RA03.04: COMPARISON OF THE CLINICAL OUTCOMES OF ESOPHAGECTOMY AND CHEMORADIOTHERAPY AFTER NONCURATIVE ENDOSCOPIC SUBMUCOSAL DISSECTION FOR ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Endoscopic submucosal dissection (ESD) is widely used to treat esophageal cancer, but some patients require additional definitive treatment owing to the possibility of residual tumor cells or lymph node metastasis. The aim of this study was to elucidate the efficacy and clinical outcomes of these additional treatments. Methods ESD was performed for cT1a esophageal cancer, and additional definitive treatment was recommended for patients who had undergone noncurative ESD for submucosa (SM) or muscularis mucosae cancers with lymphovascular invasion and a positive resection margin. The study included 59 patients who developed superficial esophageal squamous cell carcinoma after noncurative ESD treated between 2005 and 2016, of whom 28 underwent esophagectomy with lymph node dissection and 31 received chemoradiotherapy (CRT) by choice or because their conditions did not permit surgery. Results The median follow-up periods were 45 months (range, 3–89 months) in the esophagectomy group and 41 months (range, 12–84 months) in the CRT group. Overall survival didn’t differ between the groups (P = 0.46). But there were no recurrences in the esophagectomy group, and the disease-specific survival rate was significantly higher in this group (P = 0.042). Among the patients at high risk for recurrence owing to massive tumor invasion (≥ SM2) with lymphovascular invasion (esophagectomy group, 6 patients; CRT group, 10 patients), none in the esophagectomy group had a recurrence, whereas 4 in the CRT group died of esophageal cancer (P = 0.031). Conclusion Overall survival did not differ between the esophagectomy and CRT groups after noncurative ESD. However, compared with CRT, esophagectomy provided more favorable disease control for patients with massive tumor invasion (≥ SM2) with lymphovascular invasion. Disclosure All authors have declared no conflicts of interest.