PROGNOSTIC IMPACT OF BRANDWEIN-GENSLER HISTOLOGIC RISK SCORE AND TUMOR-INFILTRATING LYMPHOCYTE SUBSETS IN ORAL SQUAMOUS CELL CARCINOMA

Background Despite improvements in treatment modalities, 5-year survival of oral squamous cell carcinoma (OSCC) is static. There is a shift in focus from tumor cell biology to tumor host interactions, which serve as novel, relatively unexplored avenues for identification of prognostic/predictive biomarkers. The Brandwein-Gensler Histological Risk Score (BG-score) is a scoring system based on parameters assessing tumor host interactions. Tumor-infiltrating lymphocytes (TILs) are the major immune cells in the OSCC microenvironment. Objective To assess the impact of BG-score and TIL subsets on patient outcomes in OSCC. Methods BG-score was calculated for 178 OSCC excisions and cases were classified into low-, intermediate-, and high-risk groups. Immunohistochemistry for TIL subsets was performed in 50 cases. Results were correlated with disease-free survival and overall survival. Results Twenty-five low-risk (14%), 93 intermediate-risk (52%), and 60 high-risk (34%) cases were identified. Two-year disease-free survival and overall survival were 22.5% and 34.8% for high-risk cases, 57% and 68.8% for intermediate-risk cases, and 96% and 96% for low-risk case. BG-score coupled with pathological stage had greater predictive value (78.8%) than BG-score (69%) or pathological stage (72.5%) alone. High CD8 count, low FOXP3 count, and CD8:FOXP3 ratio >1.46 were significantly associated with improved survival. Conclusions BG-score is a simple risk assessment technique with high prognostic impact. Tumor host immune response has a significant impact on prognosis, with increased CD8+ and low FOXP3+ cells being associated with improved outcome. A case is made for BG-score and TIL subset identification to be incorporated into routine histopathologic evaluation of OSCC as biomarkers for risk stratification and planning adjuvant treatment.