Discovery and validation of a prognostic SPP1/PLAU signature in HPV-negative oropharyngeal squamous cell carcinoma

Background This study aimed to identify and validate robust prognostic biomarkers for oropharyngeal squamous cell carcinoma (OPSCC), with a specific focus on the high-risk HPV-negative subtype.Methods Integrated bioinformatics analysis was performed on transcriptomic data from four GEO datasets (n = 418 samples). Differentially expressed genes (DEGs) were identified, and a protein-protein interaction (PPI) network was constructed for the most dysregulated genes. Key modules were analyzed via survival analysis and multivariate Cox regression. The top candidate genes were validated at the protein level using immunohistochemistry (IHC) in an independent cohort of 304 OPSCC patients.Results A 33-gene module related to extracellular matrix organization showed significant prognostic association. It stratified patients into high- and low-risk groups with markedly different overall survival (HR = 2.71, p Conclusion The SPP1/PLAU dual-gene signature is a robust and independent prognostic biomarker for OPSCC, with particular clinical utility for stratifying high-risk HPV-negative patients.