Background and objective: Nodal metastasis is one of the strongest predictors of outcomes in oral cavity squamous cell carcinomas (OSCC). The aim was to analyze the interplay of nodal characteristics in OSCC prognosis.
Methods: In this retrospective cohort study we included OSCC patients treated with primary surgery including neck dissection between 2005 and 2015 (n = 619). Disease-specific survival (DSS) was the primary endpoint. Optimal cutoffs were identified using recursive-partitioning analysis (RPA). A novel characteristic-metastatic focus-to-lymph node size ratio (MLR)-was introduced. We compared the American Joint Committee on Cancer, Eighth Edition (AJCC8) pN categories to a new categorization.
Results: Patients with higher neutrophil-to-lymphocyte ratio had more adverse nodal characteristics. All nodal characteristics were significant predictors of DSS in univariable analysis. In multivariable analysis, only number of positive nodes and MLR remained significant. An RPA including all nodal covariates confirmed the results. Compared with AJCC8, our RPA categorization had better hazard discrimination (0.681 vs. 0.598), but poorer balance value (0.783 vs. 0.708).
Conclusion: Patients with higher neutrophil-to-lymphocyte ratio had more adverse nodal characteristics. Total number of metastatic lymph nodes is the strongest predictor of outcomes in OSCC. MLR is a more powerful predictor than metastatic lymph node size or metastatic focus size alone.
Keywords: American Joint Committee on Cancer; lymph node metastasis; metastatic focus-to-lymph node size ratio; oral neoplasms; prognosis.
© 2020 Wiley Periodicals LLC.