Comparison of survival and establishment of prognostic models for patients with locally advanced squamous cell carcinoma of the hypopharynx at different sites: A retrospective study based on the SEER database

Objective To assess the overall survival (OS) and cancer-specific survival (CSS) in patients with different primary locations of hypopharyngeal squamous cell carcinoma (HSCC) and to develop a predictive model incorporating key clinical and treatment variables (including systemic therapy) to serve as a prognostic reference for patients with locally advanced HSCC. Methods This retrospective cohort study extracted data for 1,591 patients with locally advanced HSCC from the Surveillance, Epidemiology, and End Results (SEER) database. X-tile software was used to determine optimal cutoff values for continuous variables. Kaplan–Meier analysis compared survival by primary site. Independent risk factors were identified using stepwise Cox regression, and a nomogram was constructed. Model performance was assessed using the concordance index (C-index), area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA). Results OS and CSS differed significantly by primary site. Stepwise Cox analysis identified 13 independent prognostic factors. The nomogram showed a C-index of 0.727 in both training and validation sets. The AUCs for 1-, 3-, and 5-year OS were 0.792, 0.791, 0.788 (training) and 0.780, 0.796, 0.789 (validation). Calibration curves indicated good agreement between predicted and observed outcomes. DCA demonstrated superior net benefit over TNM staging alone. Conclusion Prognosis in locally advanced HSCC varies by primary site. The developed nomogram provides moderate prognostic accuracy and may serve as a supplementary tool for risk stratification and clinical discussion, though external validation is warranted.