Comparing prognostic utility between the 8th edition of TNM staging system and the lymph node ratio for oral squamous cell carcinoma.

Background Lymph node metastasis in oral squamous cell carcinoma (OSCC) is associated with poor prognosis. The 8th edition of TNM has implemented new nodal staging criteria. We assess the prognostic utility of the lymph node ratio (LNR) and compare it to that of pN in the TNM 8th edition. Methods One hundred and forty-two patients with OSCC were retrospectively studied. Nodal staging was performed using the TMN 8th edition and the prognostic value of the LNR in terms of overall survival (OS) and disease-free survival (DFS) was evaluated. Results Fifty-seven patients were eligible for inclusion. The LNR was independently prognostic of OS (p = 0.02). Instead N classification was not significantly predictive of OS (p = 0.10). High LNRs resulted in decreases in OS of approximately 40% within 6 months after surgery. Conclusions The LNR identifies patients with poor outcomes better than N classification. The lack of reliable LNR cutoffs compromises its utility in clinical practice.