Efficacy of local consolidative radiotherapy with first-line chemoimmunotherapy in synchronous oligometastatic esophageal squamous cell carcinoma.

Background: Synchronous oligometastatic esophageal squamous cell carcinoma (SOESCC), characterized by a limited number of metastases at diagnosis, represents a significant subset of esophageal squamous cell carcinoma. However, the optimal treatment modality for the condition has not been determined. Therefore, we aimed to evaluate the efficacy of local consolidative radiotherapy (cRT) for the primary tumor combined with first-line chemoimmunotherapy (CIT). Methods: This retrospective cohort study included 102 patients with SOESCC who underwent first-line CIT, either alone or in combination with cRT, between 2018 and 2022. We analyzed the progression-free survival (PFS) and overall survival (OS) in the two groups using propensity score matching (PSM). Univariate and multivariate Cox regression analyses were performed to identify prognostic factors associated with PFS and OS. Failure patterns were compared between groups. Results: Patients who received the additional cRT had longer PFS (median PFS, 11.5 Conclusions: In patients with SOESCC, the combination of local cRT and first-line CIT prolonged PFS without increasing treatment-related toxicity. In addition, cRT for primary tumor significantly reduced the incidence of locoregional failure. This synergistic approach appears to be a viable and potentially superior treatment strategy for the treatment of SOESCC.