Salvage Chemoradiotherapy for Loco-Regional Recurrence of Esophageal Squamous Cell Carcinoma After Esophagectomy.

Background/Objectives: Loco-regional recurrence (LRR) of esophageal cancer following esophagectomy presents a significant therapeutic problem. This study aimed to evaluate the effectiveness of salvage concurrent chemoradiotherapy (CCRT) and to identify the prognostic factors influencing the survival outcomes in patients with an LRR of esophageal cancer. Methods: This retrospective study included 68 patients who underwent salvage CCRT for an LRR of esophageal squamous cell carcinoma between April 2008 and June 2024. Patients were treated with either 50.4 Gy in 28 fractions or 60 Gy in 30 fractions, along with concurrent fluoropyrimidine- and platinum-based chemotherapy. Prognostic factors were identified using univariate and multivariate Cox proportional hazards models. Results: The median overall survival (OS) was 30.1 months (95% confidence interval [CI]: 21.5-110.7 months), with a 2-year OS rate of 57.4%. The median progression-free survival (PFS) was 8.9 months (95% CI: 6.3-17.7 months). In the multivariate analysis, the significant prognostic factors for OS included the interval to recurrence (>1 year vs. ≤1 year, hazard ratio [HR] = 2.307, p = 0.024) and radiotherapy dose (60 Gy vs. 50.4 Gy, HR = 2.414, p = 0.040). For PFS, the interval to recurrence and radiotherapy dose remained significant predictors (p < 0.05). The 2-year OS rate was higher in the 60 Gy arm (62.7% vs. 42.0%, p = 0.285) and in patients with recurrence occurring >1 year after surgery (73.4% vs. 29.9%, p = 0.0054). The local control rate at 2 years was 71.9%, with better outcomes observed in the 60 Gy arm (93.5% vs. 76.5%, p = 0.0651). Conclusions: Salvage CCRT is a viable treatment option for LRR of esophageal cancer, achieving favorable survival outcomes, particularly in patients with late recurrence (>1 year) and in those receiving higher radiotherapy doses.