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

The eighth edition of the American Joint Committee on Cancer (AJCC) staging system incorporated pathologic depth of invasion (pDOI) and pathologic extranodal extension (pENE) for prognostic stratification in oral squamous cell carcinoma (OSCC). However, the extent of stage migration and the consistency of survival discrimination across populations remained controversial. This study aimed to evaluate stage migration associated with the AJCC 8th edition, assess its prognostic performance relative