Tumor-Stroma Ratio, Infiltrating Lymphocytes, and Their Combined Profiles in Oral Cancer Prognosis.

Background: Tumor microenvironment and immune response-related histopathological features were identified as potential biomarkers in many tumor types, including oral squamous cell carcinoma (OSCC). We assessed the prognostic significance and correlations of tumor-stroma ratio (TSR), tumor-infiltrating lymphocytes (TILs), and their combined profiles in OSCC.

Methods: The study included 114 patients with resected OSCC. Stromal TILs and TSR were evaluated on the hematoxylin and eosin-stained tissue sections according to International Immuno-Oncology Biomarker Working Group criteria and recommendations for the assessment of TSR and categorized (into stroma-high and stroma-low; TILs high and TILs low). Clinicopathological correlations and survival analyses were performed.

Results: Correlations of TSR and TILs with clinicopathological parameters, including grade, stage, perineural invasion, and lymph node metastasis, were found. TSR (stroma-high) was independently associated with shortened disease-specific, disease-free, and overall survival. Low TILs were associated with worse survival rates; these associations were not significant in multivariate analysis. However, the combined profiles of TILs with TSR showed a gradually increased risk of recurrence or death, from stroma-low/TILs high to stroma-high/TILs low tumors.

Conclusion: The findings support that the evaluation of TSR, TILs, and their combinations provides significant information on OSCC hazard discrimination and prognostication, suggesting their potential implementation in routine pathological reports.