Effectiveness of Chemoradiotherapy for Metachronous Esophageal Squamous Cell Carcinoma

Introduction: Multiple Lugol-voiding lesions (LVLs) in the esophagus increase the risk of synchronous and metachronous development of esophageal squamous cell carcinoma (ESCC). Chemoradiotherapy (CRT) following endoscopic submucosal dissection (ESD) may reduce the incidence of metachronous ESCC, but few studies have investigated this. Therefore, we retrospectively examined the effect of CRT on metachronous ESCC and multiple esophageal dysplasias visible as multiple LVLs. Methods: This study reviewed 146 patients who underwent esophageal ESD and were determined pathologically to have noncurative resection. They were divided into 2 groups: those who received additional CRT (CRT group; n = 64) and those without additional treatment (control group; n = 82). Incidence of metachronous ESCC was analyzed using propensity scores to adjust for patient characteristics. The number of multiple LVLs was also examined. Results: The CRT group was significantly younger than the control group (mean 66.6 vs. 70.6 years, p = 0.011), had significantly deeper tumor invasion (p = 0.013), and had a significantly higher rate of lymphovascular invasion (47.8 vs. 12.2%, p < 0.001). The CRT group also had a significantly higher improvement rate of multiple LVLs (58.1 vs. 2.0%, p < 0.001). The LVLs after CRT had a distinctive irregular crack-shaped appearance. Metachronous ESCC was found in 7 patients (10.9%) in the CRT group and in 17 patients (20.7%) in the control group (p = 0.113). In propensity score-adjusted logistic regression analysis, the odds ratio for metachronous ESCC in the CRT group was 0.316 (p = 0.023). The occurrence rate was significantly lower in the CRT group than in the control group. Discussion/Conclusion: CRT may be effective in preventing metachronous ESCC.