Tumor–Stroma Ratio in Head and Neck Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Background: Tumor-stroma ratio (TSR) has been recognized as a significant prognostic factor in various cancers. This systematic review evaluates the role of TSR in head and neck squamous cell carcinoma (HNSCC) and its association with patient outcomes such as overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), and lymph node metastasis (LNM). Methods: A comprehensive search was conducted across Scopus, Embase, PubMed, and Web of Science. Nineteen studies were included. Data extraction and quality assessment were performed progressively, with meta-analyses. All studies assessed TSR using hematoxylin and eosin staining of tissue samples. The meta-analyses focused on the impact of TSR on OS, DFS, DSS, and LNM, providing pooled hazard ratios (HRs) and odds ratios (ORs) with corresponding confidence intervals (CIs). Results: Meta-analysis revealed a significant association between TSR and OS (HR 1.99, 95% CI 1.71–2.32, p < 0.001), DFS (HR 2.07, 95% CI 1.80–2.39, p < 0.001), DSS (HR 2.33, 95% CI 1.95–2.78, p < 0.001), and LNM (OR 1.76, 95% CI 1.15–2.70, p = 0.01). Minimal to low heterogeneity was detected among studies, and no publication bias was observed. Conclusions: TSR can effectively identify high-risk patients, being a reliable prognostic marker that could be readily integrated into routine pathology practice for HNSCC.