Endoscopic findings suggestive of a high risk of non-radical cure after definitive chemoradiotherapy for cT1bN0M0 esophageal squamous cell carcinoma

Background Definitive chemoradiotherapy (DCRT) is a curative treatment option for cT1bN0M0 esophageal squamous cell carcinoma (ESCC); however, local residual disease and recurrence after complete remission may occur. We aimed to identify endoscopic findings associated with the risk of non-radical cure (local remnant or recurrence) after DCRT for cT1bN0M0 ESCC. Methods We retrospectively analyzed 40 consecutive patients with cT1bN0M0 ESCC who had undergone DCRT between January 2007 and December 2017. We examined the endoscopic findings in patients with residual or recurrent (RR) disease (RR group) and those without RR disease [non-RR (NRR) group] after DCRT. We also evaluated outcomes after DCRT for each endoscopic finding. Results There were 10 patients in the RR group and 30 patients in the NRR group. The RR group had a significantly larger tumor size and a higher proportion of lesions with type 0–I. The 5-year relapse-free survival rate was significantly lower in type 0–I and in the presence of B3 vessels. Endoscopic findings in 15 patients with cT1bN0M0 ESCC, type 0–I, who underwent DCRT revealed significantly more reddish lesions in the RR group compared to the NRR group. Conclusions cT1bN0M0 ESCC large size, with B3 vessels, and type 0–I has a high risk of non-radical cure after DCRT, especially the reddish type 0–I, which may need to be considered for treatment similar to advanced cancer, including surgery with preoperative DCRT.