Adjuvant Radiotherapy Improves Survival for T1b Superficial Esophageal Cancer with Lymphovascular Invasion after Endoscopic Resection

Abstract

<h3>Purpose/Objective(s)</h3> Several studies, including the multicenter prospective trial JCOG 0508, have reported a higher risk of recurrence in patients with pT1b esophageal carcinoma (EC) with lymphovascular invasion (LVI) after endoscopic resection (ER). The role of adjuvant radiotherapy in this population has not been fully proven. Thus, the aim of this study was to investigate the effectiveness of adjuvant radiotherapy for T1b EC with LVI. <h3>Materials/Methods</h3> This was a multicenter retrospective study including 6 centers in China. From May 2011 to March 2019, patients with T1b EC and LVI who underwent ER with or without radiotherapy were included and analyzed. The overall survival (OS) and disease-free survival (DFS) were estimated by the Kaplan-Meier method, and the log-rank test was used to analyze differences between the groups. Factors between different groups were compared using chi square test. <h3>Results</h3> A total of 42 patients were included, including 37 (88.1%) males and 5 (11.9%) females. The median age was 60 (49-80) years old. Forty (95.2%) patients were squamous cell carcinoma, and two (4.8%) were adenosquamous cell carcinoma. The number of patients with tumor of SM1 and SM2 invasion were 10 (23.8%) and 32 (76.2%), respectively. The median lesion length was 3.0 cm. Thirty-six (85.7%) Patients underwent complete ER and six (14.3%) patients were with R1 resection. Sixteen (38.1%) patients received adjuvant radiotherapy, including two received chemoradiotherapy. The factors mentioned above were well balanced between radiotherapy and non-radiotherapy groups. The median survival in the radiotherapy vs. non-radiotherapy groups were not reached vs. 80.4 months, respectively. The 3y- and 5y-OS were 91.7% and 91.7% in the radiotherapy group vs. 80.8% and 58.9% in the non-radiotherapy group, respectively (p=0.045). The median DFS time in the radiotherapy vs. non-radiotherapy groups was not reached vs. 43.8 months, respectively. The 3y- and 5y-DFS were 92.9% and 92.9% in the radiotherapy group vs. 69.2% and 43.5% in the non-radiotherapy group, respectively (p=0.011). Radiotherapy was the only prognostic factor for both OS and DFS. <h3>Conclusion</h3> Adjuvant radiotherapy improved the survival of patients with T1b EC with LVI after ER. This combined treatment strategy could cure T1b-LVI EC while preserving the esophagus.