The Prognostic Role of Tumor-Stroma Ratio in Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis.

BACKGROUND: The tumor-stroma ratio (TSR) has emerged as a potential prognostic marker in several cancers, including oral squamous cell carcinoma (OSCC). However, results with high certainty of evidence are required for its implementation in routine histological analysis. Therefore, this systematic review aims to summarize the evidence on the prognostic role of the TSR in OSCC. METHODS: A search was performed in Embase, PubMed, Scopus, Livivo, Web of Science, and Google Scholar. We included cohort studies that evaluated the association between TSR and survival. Reviews and studies that did not report hazard ratio (HR) were excluded. RESULTS: This systematic review included 10 studies and showed an association between TSR and survival. Low TSR (stroma-rich) was associated with decreased overall survival (OS) in univariate analysis (HR = 3.00, 95% CI: 1.69-5.30, p<0.01) and multivariate analysis (HR = 2.91, 95% CI: 2.19-3.87, p<0.01); poorer disease-specific survival (DSS) in univariate analysis (HR = 2.57, 95% CI: 1.95-3.39, p<0.01) and multivariate analysis (HR = 2.64, 95% CI: 1.83-3.79, p<0.01); and poorer disease-free survival (DFS) in univariate (HR = 2.56, 95% CI: 2.02-3.23, p<0.01) and multivariate analyses (HR = 2.11, 95% CI: 1.74-2.56, p<0.01). CONCLUSION: Our findings indicate that TSR is an independent prognostic factor for OS, DSS, and DFS in oral squamous cell carcinoma. However, future studies are needed to assess the prognostic role of this histopathological parameter in OSCC to increase the certainty of the evidence.