Tumor-host interface in oral squamous cell carcinoma: Impact on nodal metastasis and prognosis

Purpose To evaluate tumor-host interface in oral squamous cell carcinoma (OSCC) by the Brandwein-Gensler histological risk score (BG risk score); to assess its association with clinicopathological features and impact on survival outcomes in a contemporary cohort staged as per AJCC 8th edition pTNM classification. Methods This retrospective cohort study at a tertiary care centre included 178 cases of OSCC treated by primary surgical resection from 2013 to 2016. Pathological lymph node status, disease-free survival (DFS), overall survival (OS) were assessed. Results BG risk score assessment categorized 25 (14%) cases as low-risk, 93 (52%) as intermediate-risk, and 60 (34%) as high-risk. BG risk score category progression from low to intermediate to high risk was associated with an incremental risk of worsening pN status, DFS, and OS. BG risk score categories significantly demarcated 2-year DFS (96% in low-risk, 51.6% in intermediate-risk, 15% in high-risk; p < 0.001) and OS (96% in low-risk, 66.7% in intermediate-risk, 31.3% in high-risk; p < 0.001). On stratified analysis, BG risk score could further demarcate prognosis in early (I/II) and late (III/IV) stage subgroups ( p < 0.001). Multivariate analysis indicated the prognostic impact of BG risk score categories to be additional to, and of equal magnitude to, impact of pTNM stage. Conclusions BG risk score is a powerful prognostic tool in OSCC additional to pTNM staging. It can enable risk stratification and inform decisions regarding post-surgical adjuvant treatment. It is undertaken with routine histopathological evaluation, with no increased expense or turnaround time. A case is made for its inclusion in OSCC reporting guidelines.