Stage migration and prognostic refinement of oral squamous cell carcinoma under the AJCC 8th edition staging system: a retrospective cohort study with additional evaluation using the SEER database

CONCLUSION: The AJCC 8th edition improved prognostic stratification in OSCC, particularly for intermediate and advanced-stage disease. However, residual prognostic overlap remained between specific pT categories. The exploratory refinement of selected pT thresholds may modestly improve prognostic accuracy. However, rigorous validation in larger independent external cohorts is required before its clinical applicability can be determined.