Abstract: Objective To establish and validate a nomogram model for predicting overall survival (OS) in the elderly patients with esophageal cancer treated with immune checkpoint inhibitors (ICIs). Methods The clinical data of the elderly patients with esophageal cancer treated with ICIs at the First Affiliated Hospital with Nanjing Medical University from December 2019 to June 2024 were retrospectively analyzed. The independent prognostic factors were identified using Cox regression combined with stepwise regression based on laboratory data within two weeks before the first immunotherapy session. A predictive nomogram model was constructed and internally validated. Results Geriatric nutritional risk index (GNRI), neutrophil-to-lymphocyte ratio (NLR), M-stage, surgery, and carcinoembryonic antigen (CEA) were independent predictors of OS in elderly patients with esophageal cancer treated with ICIs (P<0.05). The consistency index (c-index) was 0.806 of the predictive model. After 1000 times of Bootstrap resampling validations, the corrected c-index was 0.815.Calibration curves closely matched the ideal line. The area under the curve (AUC) for 1-year and 2-year survival was 0.81 (95%CI: 0.72－0.90) and 0.88 (95%CI: 0.82－0.95) respectively. Decision curve analysis (DCA) confirmed the clinical utility of the model. Conclusions GNRI, NLR, M-stage, surgery, and CEA are valuable prognostic markers for elderly esophageal cancer patients treated with ICIs. The developed nomogram provides an effective tool for individualized survival prediction.

Key words: esophageal cancer, immunotherapy, nomogram, influencing factors, aged