Predictors of locoregional control in stage I/II oral squamous cell carcinoma classified by AJCC 8th edition.

OBJECTIVES: To study the determinants of locoregional control (LRC) on stage I/II oral squamous cell carcinoma (OSCC) classified by AJCC 8th edition. METHODS: Retrospective analysis from 296 patients of pT1-2N0 oral OSCC treated with surgery (wide local excision and selective neck dissection). Those receiving adjuvant therapy were excluded. Multivariate analysis was performed for impact of adverse pathological features (APFs) on LRC. RESULTS: In stage I, LRC was impacted by perineural invasion (PNI) (HR 7.72, p = 0.010, 95% CI 1.64-36.26) and moderate/poor differentiation (MD/PD) (HR 3.04, p = 0.049, 95% CI 0.99-9.25). In stage II, LRC was impacted by depth of invasion (DOI) (HR 1.59, p = 0.014, 95% CI 1.099-2.32), PNI (HR = 2.86, p = 0.005, 95% CI 1.36-5.98). Combined MD/PD and PNI were associated with worse LRC than either feature individually (HR = 4.12, p < 0.001, 95% CI 2.16-7.85). CONCLUSION: PNI and differentiation accurately predict LRC in AJCC 8th edition classified stage I/II OSCC. PNI was a stronger predictor of locoregional failure than DOI in stage II disease. By incorporating these parameters, we can improve precision in staging of early OSCC and identify potential candidates for treatment escalation to improve outcomes.