Is chemoradiotherapy equivalent to surgery for cT1bN0M0 esophageal cancer? A multicenter retrospective study (Korean Radiation Oncology Group 21-10)

Introduction: While esophagectomy remains the standard of care for cT1bN0M0 esophageal squamous cell carcinoma (ESCC), definitive chemoradiotherapy (DCRT) offers a potential organ-preserving alternative. This study aimed to evaluate the equivalence of DCRT and esophagectomy in this patient population. Materials and methods: Medical records of patients with cT1bN0M0 ESCC treated between January 2010 and April 2020 were retrospectively reviewed. Patients were divided into the surgery and DCRT groups. Disease recurrence and overall survival (OS) were compared between two groups. Propensity score matching (PSM) and age-comorbidity subgroup analyses were performed to adjust for baseline differences. Results: A total of 333 and 88 patients who had undergone esophagectomy and DCRT, respectively, were included. Patients in the surgery group were significantly younger and had better performance status than those in the DCRT group. Clinical complete response was achieved in 84 patients (95.5 %) following DCRT. With a median follow-up of 55 months (range, 0.4–134), disease recurrences was observed in 19.2 % (64 patients) and 17.0 % (15 patients) in the surgery and DCRT groups, respectively. Although the surgery group displayed a trend toward improved OS (77.8 % vs. 65.8 %, p = 0.072) in initial analysis, no significant difference in disease-free survival (DFS) was observed between the groups (78.5 % vs. 74.7 %, p = 0.854). After PSM, the survival differences disappeared, demonstrating equivalent OS, locoregional DFS (LRDFS), and DFS. DCRT was associated with significantly better distant DFS (DDFS) (p = 0.011). Conclusions: DCRT was equivalent to esophagectomy in terms of LRDFS, DFS, and OS rates in patients with cT1bN0M0 ESCC.