Prognostic Value of Lymph Node Density in Node-Positive Patients with Oral Squamous Cell Carcinoma

Lymph node density (LND) is superior to TNM nodal status in predicting survival after surgery for bladder and other cancers. Little is known, however, about whether LND can predict survival in patients with oral squamous cell carcinoma (OSCC). We therefore evaluated the utility of LND for predicting survival for patients with OSCC and positive nodes (pN+). We reviewed the clinical, pathologic, and follow-up data of 211 OSCC patients who underwent surgery. All lymph nodes harvested from neck dissection were carefully examined, with LND calculated as the ratio of positive lymph nodes to total lymph nodes removed. Univariate and multivariate analyses of variables predicting overall survival (OS) and disease-specific survival (DSS) were performed for all patients and in pN+ patients. Kaplan-Meier analyses showed that the 5-year OS and DSS rates in all patients were 72% and 79%, respectively. Multivariate analysis showed that variables independently prognostic for DSS were T classification (hazard ratio [HR] = 2.97, 95% confidence interval [95% CI] = 1.59-5.57; P = .001), and N classification (HR = 4.91, 95% CI = 2.47-9.75; P < .001). In pN+ patients, univariate analysis showed that T classification, > 2 positive nodes, and LND > 0.06 (median) were significant predictors of DSS (P < .015 each), and multivariate analysis showed that LND was an independent predictor of DSS (HR = 3.24, 95% CI = 1.61-6.53; P = .001). LND may be useful in stratifying the likelihood of survival in patients with OSCC.