Tumor-stroma ratio can reliably be assessed in pre-treatment biopsies, shows substantial agreement with resections, and is significantly associated with overall and recurrence-free survival in early-stage oral squamous cell carcinomas

Abstract

Abstract Objectives Early-stage oral squamous cell carcinomas (OSCC) are a heterogeneous group of tumors in terms of patients’ outcomes, and the current TNM classification is often insufficient to predict the clinical course. Recently, tumor-stroma ratio has been shown to better stratify patients into low- and high-risk groups. This study aims to assess whether pre-treatment biopsies can be used for this purpose and correlates findings with resections as well as survival. Materials and Methods 66 resection specimens of early-stage OSCC (UICC stages I and II) and 50 corresponding pre-treatment biopsies were analyzed. Tumor-stroma ratio was determined with a cut-off of 50%. The Kappa correlation coefficient was used to determine the agreement between resections and biopsies. Kaplan-Meier curves for overall and recurrence-free survival were created, and a p-value < 0.05 indicated a significant correlation in all analyses. Additionally, cox proportional hazard analysis (univariate) was performed to test for independence. Results There was substantial agreement between preoperative biopsies and surgical specimens (Kappa correlation coefficient: 0.655). Stroma-rich tumors were associated with significantly decreased overall and recurrence-free survival in both resections and biopsies (p-values < 0.0001 and 0.039). Cox proportional hazard analysis revealed tumor-stroma ratio as an independent prognostic factor, with hazard ratios between 2.81 and 12.46 (p-values 0.002 and 0.049).