Abstract
BACKGROUND: Immune checkpoint inhibitors (ICIs) such as pembrolizumab (Pem) have demonstrated clinical benefits in esophageal cancer. Cisplatin, 5-fluorouracil, and Pem combination (CF plus Pem) has emerged as a promising first-line regimen. However, dose reduction of cytotoxic agents is necessary in real-world practice in patients with advanced age and/or renal dysfunction. This study aimed to evaluate the real-world effectiveness and safety of CF plus Pem therapy and assess survival outcomes based on the initial dose intensity. METHODS: We retrospectively analyzed patients with unresectable or recurrent esophageal cancer who received CF plus Pem between February 2022 and February 2025. Clinical data, including patient characteristics, treatment details, tumor response, adverse events, and survival outcomes, were collected and analyzed. RESULTS: We included 54 patients (median age, 72.5 years; 74.1% male). The initial CF dose was reduced in 55.6% of the patients. The overall response and disease control rates were 55.6% and 81.5%, respectively. The median overall survival (OS) and progression-free survival (PFS) were 18.6 and 6.5 months, respectively, with no significant differences observed among groups based on dose reduction, age, or change in treatment interval. Grade ≥ 3 adverse events occurred in 16.7% of patients, with fewer events and higher treatment continuity in the dose-reduction group. CONCLUSIONS: Thus, CF plus Pem therapy is effective and tolerable in real-world settings. Initial dose reduction does not compromise survival and supports individualized dosing strategies for esophageal cancer treatment.