Purpose of review The purpose of this review is to highlight the most important changes in the eighth TNM classification system for oral squamous cell carcinomas compared with the seventh edition with focus on lymph node staging (pN). Nodal involvement is crucial when addressing prediction of survival, and staging must mirror the disease extension. pN classification will be evaluated with respect to lymph node yield (LNY), lymph node density (LND), and a recently proposed classification: pN-N+ reflecting positive regional lymph nodes (metastatic burden) and extra nodal extension. Recent findings TNM8 was introduced in 2018, and the most noteworthy changes were depth of invasion (DOI) and extranodal extension (ENE). Recent studies indicate, that TNM8-related pN is not superior to TNM7 with respect to predicting survival. LNY and LND are biased with ecological interference fallacy, and currently not recommended in future iterations of TNM. In contrast, the pN-N+ classification has demonstrated improved survival prediction compared with TNM8. Summary The recent findings support the inclusion of pN-N+, that is, metastatic burden and extranodal extension in future iterations of TNM.
