Spatial Remodeling of the Immune Microenvironment During Laryngeal Carcinogenesis Reveals Prognostic Immune Patterns in Laryngeal Squamous Cell Carcinoma

Background/Objectives: Despite therapeutic advances, laryngeal squamous cell carcinoma (LSCC) remains a clinical challenge. We investigated immune microenvironment remodeling and its prognostic relevance during laryngeal carcinogenesis. Methods: This retrospective study included 227 patients: 45 with benign laryngeal polyps, 55 with laryngeal epithelial dysplasia, and 127 with LSCC; 55 (43.3%) LSCCs were Union for International Cancer Control (UICC) stage I–II and 72 (56.7%) stage III–IV. Immunohistochemistry on tissue microarrays (TMAs) was used to assess the density of cluster of differentiation (CD)4-, CD8-, forkhead box P3 (FOXP3)-, programmed cell death protein 1 (PD-1)-, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4)-, CD68-, and CD163-positive immune cells, together with FOXP3/CTLA-4 double-positive cells. Immune-cell densities were expressed as the percentage of the respective intraepithelial/intratumoral or stromal compartment occupied by positively stained immune cells. An exploratory Protective Immune Score (PIS; 0–2) assigned one point each for high intraepithelial FOXP3 and high stromal CTLA-4 cell density. Results: LSCC showed increased stromal immune-cell density and coordinated immune organization. Stromal PD-1 correlated with CD4, CD8, and FOXP3 density (rs = 0.561, 0.515, and 0.403), and stromal CTLA-4 with FOXP3 (rs = 0.556; all p < 0.0001). High intraepithelial FOXP3 was associated with improved disease-specific survival (DSS; hazard ratio [HR] = 0.26, 95% confidence interval [CI] 0.10–0.72) and disease-free survival (DFS; HR = 0.24, 95% CI 0.10–0.59). High stromal CTLA-4 similarly favored DSS (HR = 0.29, 95% CI 0.11–0.74) and DFS (HR = 0.26, 95% CI 0.11–0.61). The PIS remained independently associated with DSS (adjusted HR = 0.29, 95% CI 0.16–0.55) and DFS (adjusted HR = 0.29, 95% CI 0.17–0.52). Conclusions: Laryngeal carcinogenesis is characterized by progressive, compartment-specific immune remodeling, with the stroma emerging as the principal site of coordinated immune organization. The PIS captures spatially defined favorable immune features and warrants validation in independent cohorts.