Spatial Neuroimmune Crosstalk Driving Perineural Invasion in Head and Neck Squamous Cell Carcinoma

BackgroundPerineural invasion (PNI) is a clinically important feature of aggressive head and neck squamous cell carcinoma (HNSCC) and is associated with recurrence and poor survival. However, the spatial organization and molecular programs that characterize tumor-nerve interactions in HNSCC remain incompletely understood. MethodsSingle-cell-resolution Xenium spatial transcriptomic data from 10 HNSCC patients were analyzed to define nerve-associated regions, cell-type composition, tumor-nerve proximity, and perineural transcriptional programs. Complementary Visium spatial transcriptomic datasets were used to assess broader transcriptomic features of nerve-associated regions, including epithelial-mesenchymal transition and inferred ligand-receptor signaling. Clinical relevance was evaluated using bulk transcriptomic validation cohorts from TCGA-HNSC and GSE65858. ResultsSpatial mapping identified a distinct nerve-proximal microenvironment characterized by depletion of mature dendritic cells and altered immune and stromal composition, consistent with localized disruption of antigen-presenting support at the tumor-nerve interface. HPV- tumors exhibited closer tumor-nerve proximity and a higher exploratory PNI index compared with HPV+ tumors, suggesting subtype-specific differences in nerve-associated tumor behavior. Differential expression analysis of perineural versus distal tumor cells identified a spatially enriched gene program, including NFE2L2, MDM2, and PPARG, that demonstrated a nerve-proximal gradient most evident in HPV- disease. A composite three-gene score was associated with worse overall survival in HPV- patients in TCGA-HNSC and validated in GSE65858, while showing limited prognostic value in HPV+ disease. Visium analyses provided complementary evidence of EMT enrichment and inferred tumor-nerve signaling involving neural guidance and adhesion-associated pathways. ConclusionsThese findings support a model in which PNI in HNSCC reflects a spatially organized, transcriptionally distinct tumor-nerve microenvironment, particularly in HPV- disease. The NFE2L2/MDM2/PPARG signature may provide a candidate biomarker for risk stratification and nominates pathways for future mechanistic and therapeutic investigation.