Efficacy and safety of maintenance therapy in unresectable locally advanced esophageal squamous cell carcinoma.

Abstract

e16123 Background: Esophageal cancer is an aggressive malignancy and the seventh leading cause of cancer-related mortality worldwide. The majority of patients are diagnosed at an advanced stage and are thus ineligible for surgical intervention. For patients with unresectable locally advanced esophageal squamous cell carcinoma (ESCC), there is no consensus on the clinical efficacy and safety of maintenance therapy following first-line treatment. Methods: This retrospective study analyzed 204 patients with ESCC, of whom 68 received maintenance therapy and 136 were under observation. The primary endpoints were overall survival (OS) and progression-free survival (PFS), and an exploratory analysis was performed to assess the impact of maintenance therapy duration and type on survival outcomes. Results: Multivariable Cox regression analysis demonstrated a significant improvement in overall survival (OS) with maintenance therapy (hazard ratio [HR], 0.455; 95% CI, 0.259-0.799; P = 0.006) and a trend toward improved progression-free survival (PFS; HR, 0.658; 95% CI, 0.425-1.020; P = 0.062). These findings were corroborated by a propensity score-matched sensitivity analysis. Subgroup analyses indicated OS benefits across multiple patient subsets. The most common adverse event during maintenance therapy was hypothyroidism (16.2%), which was predominantly grade 1-2. Conclusions: In patients with unresectable locally advanced ESCC, maintenance therapy is associated with a significant overall survival benefit and an acceptable safety profile.