Role of postoperative radiotherapy in locally advanced esophageal squamous cell carcinoma after neoadjuvant chemoimmunotherapy: A retrospective propensity score-matched study

Background Although neoadjuvant immunochemotherapy (NCIT) has shown promising prospects in the treatment of locally advanced esophageal squamous cell carcinoma (LA-ESCC), the role of adjuvant radiotherapy in these patients remains unclear. Objectives This study aimed to investigate the impact of postoperative adjuvant radiotherapy on treatment outcomes in patients with LA-ESCC who underwent NCIT and surgery. Design This retrospective cohort study used propensity score matching (PSM) to balance baseline characteristics. Methods This study included patients with LA-ESCC who underwent NCIT and achieved R0 resection between January 2020 and December 2023, and divided them into a postoperative adjuvant radiotherapy group (PORT) and a non-adjuvant radiotherapy group (non-PORT). PSM was used to balance the two groups on covariates. The primary endpoints were to compare disease-free survival (DFS) and overall survival (OS), and to evaluate treatment-related adverse events (AEs). Results A total of 318 patients were included in the study. The 2-year DFS and OS rates in the overall population were 68.1% and 81.1%, respectively. After PSM, median DFS was 17.96 months in the non-PORT group, whereas it was not reached (NR) in the PORT group (HR=0.527, 95%CI: 0.329-0.843, p=0.007). The median OS was NR in either group, with 2-year OS rates of 83.5% and 62.0%, respectively (p=0.005). The PORT group had a higher incidence of Grade 3 and Grade 4 hematologic toxicity (25.32% vs. 18.37%), while no significant differences were observed for other Grade 3 and Grade 4 non-hematologic toxicities. Conclusions For patients with LA-ESCC who undergo NCIT and R0 resection, PORT is associated with improved DFS and shows preliminary evidence of a beneficial effect on OS, while toxicity remains within an acceptable and manageable range.