Cancer-associated fibroblasts and immune remodeling in laryngeal squamous cell carcinoma: evidence and translational perspectives

Abstract

Laryngeal squamous cell carcinoma (LSCC) remains a clinically challenging malignancy of the head and neck. Because organ preservation is a major therapeutic objective in LSCC, stromal biology is of particular clinical relevance. Stromal factors influence local disease control, functional outcomes, and treatment resistance. Cancer-associated fibroblasts (CAFs) are dynamic regulators of extracellular matrix remodeling, immune exclusion, angiogenesis, and therapeutic resistance. However, LSCC-specific evidence remains fragmented, and many mechanistic concepts are still extrapolated from head and neck squamous cell carcinoma (HNSCC) and hypopharyngeal squamous cell carcinoma (HPSCC). This review adopts an evidence-stratified framework that distinguishes direct LSCC evidence from translatable cross-site evidence and hypothesis-generating inferences. We propose a provisional five-state model for LSCC that includes myofibroblastic, inflammatory, antigen-presenting, extracellular matrix-remodeling, and putative immune-trapping CAF programs. Direct LSCC studies support the presence of early stromal activation along the leukoplakia-to-carcinoma continuum and the enrichment of FAP-positive and POSTN-positive fibroblastic programs in metastatic disease. Associations involving stromal PD-L1 expression and altered CAF-derived exosomal microRNA cargo have also been reported. Translatable evidence from HNSCC implicates TGF-β- and CXCL12-dependent T-cell exclusion together with Gal9-mediated T-cell dysfunction. Additional mechanisms include IL-6/JAK/STAT3-driven myeloid skewing and NOX4-dependent stabilization of the myofibroblastic phenotype. We integrate these findings into a spatially informed conceptual framework encompassing the invasive front, the perivascular compartment, the cartilage interface, and the lymphovascular niche. We also discuss biomarker-guided therapeutic opportunities, including CAF normalization, FAP-directed approaches, stromal signaling blockade, extracellular matrix-targeted strategies, and interference with extracellular vesicle-mediated signaling. This review thereby establishes an evidence-stratified framework for CAF heterogeneity in LSCC and clarifies the translational value and current limitations of stroma-targeted strategies. It further provides a structured foundation for hypothesis-driven clinical and experimental investigation in laryngeal cancer.