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

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.

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.

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.

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.