Concordance and Prognostic Impact of Tumor-Stroma Ratio and Tumor-Infiltrating Lymphocytes in Preoperative Biopsies and Matched Surgical Specimens in Oral Squamous Cell Carcinoma.

Background/Objectives: Tumor-stroma ratio (TSR) and tumor-infiltrating lymphocytes (TILs) were suggested as prognostic markers in oral squamous cell carcinoma (OSCC). Identification of markers assessable in preoperative biopsies that could guide treatment planning is of great importance. This study aimed to evaluate the concordance and prognostic impact of TSR and TILs in preoperative biopsies and matched resection specimens of OSCC. Methods: This study included 100 patients with OSCC. TSR and stromal TILs were evaluated on hematoxylin and eosin-stained slides of biopsies and paired resection specimens and categorized (into low TSR and high TSR; high TILs and low TILs). The agreement between resections and biopsies, and the prognostic significance and clinicopathological correlations of TSR and TILs, were investigated. Results: For TSR, substantial agreement between preoperative biopsies and surgical specimens (kappa correlation coefficient 0.713) was demonstrated. The assessment of TILs showed poor concordance between biopsies and resections (kappa correlation coefficient 0.372). For both biopsies and resections, Cox regression showed an independent negative prognostic impact of low TSR on disease-free, disease-specific, and overall survival. Independent prognostic value of TILs evaluated in biopsies was not found, and the negative prognostic impact of low TILs on disease-free and overall survival was observed only in the main resection specimens. Conclusions: TSR evaluated in preoperative biopsies was highly concordant with results in main resection specimens and may provide significant information for OSCC prognostication, risk stratification, and treatment decisions. In contrast, TILs evaluated in biopsies showed poor concordance with main resection specimens and failed to demonstrate prognostic significance.