Background: The 8th edition of the American Joint Committee on Cancer (AJCC) classification has introduced two new parameters: depth of invasion (DOI) and extranodal extension (ENE). The aim of this systematic review was to determine whether this 8th edition referred to oral squamous cell carcinoma (OSCC) offers performance superior to that of the 7th edition in relation to overall survival (OS) and disease-specific survival (DSS).
Material and methods: The review was carried out following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. The PubMed (MEDLINE), Scopus and Cochrane Library databases were searched covering the period up until April 7th, 2022.
Results: Thirteen retrospective cohort studies were finally included. The introduction of DOI and ENE in the 8th edition of the AJCC classification resulted in improved prognostic performance of the classification.
Conclusions: Patients with OSCC can be better classified in relation to OS and DSS, while maintaining the simplicity and ease of use of the classification. This allows more appropriate treatment protocols to be applied and affords a better estimation of the prognosis of each patient.