Regional Lymph-Node Failures after Diagnostic Endoscopic Resection Plus Selective Chemoradiotherapy for Clinical Stage I Esophageal Squamous Cell Carcinoma: A Multi-Institutional Phase II Study (JCOG0508)

Radiotherapy Improves Survival of Patients With Lymphovascular Invasion in pT1b Esophageal Squamous Cell Cancer After Endoscopic Submucosal Dissection

INTRODUCTION

Adjuvant radiotherapy is recommended for pT1b esophageal squamous cell cancer (ESCC) after endoscopic submucosal dissection (ESD). However, it is unclear whether additional radiotherapy can improve patient survival. This study aimed to evaluate the efficacy of adjuvant radiotherapy after ESD for pT1b ESCC.

METHODS

This was a multicenter, cross-sectional study involving 11 hospitals in China. Between January 2010 and December 2019, patients with T1bN0M0 ESCC treated with or without adjuvant radiotherapy after ESD were included. Survival between groups was compared.

RESULTS

Overall, 774 patients were screened, and 161 patients were included. Forty-seven patients (29.2%) received adjuvant radiotherapy after ESD (RT group) and 114 (70.8%) underwent ESD alone (non-RT group). There were no significant differences in overall survival (OS) and disease-free survival (DFS) between the RT and non-RT groups. Lymphovascular invasion (LVI) was the only prognostic factor. In the LVI+ group, adjuvant radiotherapy significantly improved survival (5-year OS: 91.7% vs 59.5%, P = 0.050; 5-year DFS: 92.9% vs 42.6%, P = 0.010). In the LVI- group, adjuvant radiotherapy did not improve survival (5-year OS: 83.5% vs 93.9%, P = 0.148; 5-year DFS: 84.2% vs 84.7%, P = 0.907). The standardized mortality ratios were 1.52 (95% confidence interval 0.04-8.45) in the LVI+ group with radiotherapy and 0.55 (95% confidence interval 0.15-1.42) in the LVI- group without radiotherapy.

DISCUSSION

Adjuvant radiotherapy could improve survival in pT1b ESCC with LVI+ other than LVI- after ESD. Selective adjuvant radiotherapy based on LVI status achieved survival rates similar to those of the general population.

Additional Radiotherapy With or Without Chemotherapy Following Endoscopic Resection for Stage I Esophageal Carcinoma: A Pilot Study

Objective: To evaluate the safety and efficacy of additional radiotherapy after endoscopic resection (ER) for stage I esophageal carcinoma (EC) with high-risk factors. Materials and methods: Patients with stage cT1N0M0 EC who underwent ER and additional radiotherapy between January 2010 and August 2019 at our institution were retrospectively included. Overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), local control rate, regional control rate, common acute toxicities, esophageal stricture, and dysphagia were analyzed. Results: Thirty-one consecutive patients were included in the study. The median age was 62 years (range, 49-78). Thirty patients (96.8%) had squamous cell carcinoma, and one patient (3.2%) had adenosquamous cell carcinoma. Twenty-six patients (83.9%) had submucosal invasion, 15 patients (48.4%) had lymphovascular invasion, and one patient (3.2%) had a venous invasion. The 1-, 3-, and 5-year OS rates were 100.0%, 86.9%, and 68.5%, respectively. The corresponding DFS rates were 100.0%, 85.2%, and 75.8%, respectively. The corresponding CSS rates were 100.0%, 89.8%, and 78.6%, respectively. The local and regional control rates were 100.0% and 93.5%, respectively. No grade 4-5 acute toxicities were observed. Fifteen patients (48.4%) were endoscopically diagnosed with esophageal strictures after ER. At the last follow-up, 28 patients (90.5%) were able to eat a regular diet, one patient (3.2%) could eat a soft diet, one needed a semifluid diet, and only one (3.2%) had to eat a fluid diet. Conclusions: For patients with stage I EC, additional radiotherapy following ER is safe and effective, with the swallowing function well-preserved. Nevertheless, prospective studies are needed to verify these results.