Treatment Outcomes and Significance of Multimodal Treatment in Esophageal Squamous Cell Carcinoma with Synchronous Oligometastasis

<b>Background/Objectives:</b> Synchronous oligometastasis in stage IVB esophageal squamous cell carcinoma (ESCC) may represent an intermediate state in which local therapy remains effective. However, its definition is still debated, and outcome data are limited. <b>Methods:</b> We retrospectively analyzed 191 consecutive patients with ESCC and synchronous oligometastases treated between 2006 and 2022. Oligometastasis was defined as ≤5 distant metastatic lesions. Patients received systemic therapy (chemotherapy and/or immunotherapy), local therapy (surgery or radiotherapy), or combined systemic and local therapy (surgery following preoperative therapy or chemoradiotherapy). Survival outcomes and prognostic factors were assessed. <b>Results:</b> The median overall survival (OS) was 25.1 months, with a 3-year OS rate of 41.0%. Multivariate analysis identified performance status, number of organ metastases, and treatment type as independent prognostic factors. Patients with single-organ metastasis had superior outcomes compared with those with multiple metastases (3-year OS: 44.3% vs. 0%; progression-free survival [PFS]: 23.5% vs. 0%). Combined systemic and local therapy yielded the best outcomes, with 3-year OS and PFS rates of 49.8% and 29.3%, respectively, compared with 20.0% and 18.1% for local therapy and 20.1% and 0% for systemic therapy alone. <b>Conclusions:</b> Patients with multiple-organ metastases have a very poor prognosis, indicating that their metastases may not represent true oligometastases. Long-term survival can be achieved in some patients using multimodal strategies that integrate systemic and local therapies. These findings demonstrate better treatment outcomes for stage IVB ESCC and provide a reference for future developments relating to oligometastatic disease.