High‐risk lymph node ratio predicts worse prognosis in patients with locally advanced oral cancer

BACKGROUND: To investigate the prognostic value of lymph node ratio (LNR), as well as the correlation with docetaxel, cisplatin, and 5‐FU (TPF) induction chemotherapy, in patients with locally advanced oral squamous cell carcinoma (OSCC). METHODS: Two‐hundred and forty‐five patients from a phase 3 trial involving TPF induction chemotherapy in stage III/IVA OSCC patients (NCT01542931) were enrolled in this study between 2008 and 2010. The clinical and pathological data were collected and analyzed. The cutoff value for LNR was calculated on the receiver operating characteristic (ROC) curve. Univariate and multivariate Cox regression models, and Kaplan‐Meier method were used for survival analysis. RESULTS: According to the ROC curve, the cutoff value for LNR was 7.6%. With a median follow‐up period of 80 months, the OSCC patients with high‐risk LNR (> 7.6%), or positive extranodal extension (ENE) had significantly worse clinical outcomes than patients with low‐risk LNR (≤7.6%) or negative ENE. Multivariate analysis on pathological covariates showed that only high‐risk LNR was an independent negative predictive factor for survival (P < .05). The cutoff value of LNR of 7.6% was also verified with the similar results using an open TCGA database, high‐risk LNR indicating worse overall survival (P < .001) and disease‐free survival (P < .001). CONCLUSION: Oral squamous cell carcinoma patients with high‐risk LNR have a worse clinical outcome than patients with low‐risk LNR. High‐risk LNR is an independent negative predictive factor for clinical outcome in patients with locally advanced OSCC.