Elevated Pre-Treatment Serum Interleukin-10 Levels Predict Poor Overall Survival in Esophageal Cancer.

OBJECTIVE: Our objective was to evaluate whether pre-treatment serum interleukin (IL)-10 concentrations predicted overall survival (OS) in patients with esophageal squamous cell carcinoma. METHODS: This single-center retrospective analysis included 112 patients with esophageal cancer who were treated with definitive concurrent chemoradiotherapy. Pre-treatment serum samples were collected, and IL-10 levels were measured. Patients were dichotomized into "low" and "high" IL-10 groups. Baseline characteristics (age, alcohol consumption, betel nut chewing, smoking, clinical T/N stage, Union for International Cancer Control [UICC] stage, tumor grade, primary location, and treatment) were compared using χ2 or Fisher's exact tests. OS and progression-free survival were estimated using the Kaplan-Meier method and compared using log-rank tests. Variables with p < 0.1 on univariable analysis were entered into a multivariable Cox proportional hazards model to identify independent prognostic factors. RESULTS: Baseline demographics and clinicopathological characteristics were comparable between the low- and high-IL-10 groups. The 1- and 3-year OS rates were 85% and 50% in the low-IL-10 group and 56% and 33% in the high-IL-10 group, respectively. Univariate analysis indicated that UICC stage and IL-10 level influenced prognosis. Advanced stage and high IL-10 expression were independent predictors of shorter OS and progression-free survival. Kaplan-Meier curves showed that survival diverged early between the IL-10 strata and remained separated over time. CONCLUSIONS: High pre-treatment serum IL-10 levels were associated with worse survival in patients with esophageal squamous cell carcinoma and constituted an independent prognostic factor after adjusting for clinical stage. As a minimally invasive biomarker, serum IL-10 can aid in risk stratification and may inform immunomodulatory treatment strategies.