Lymph node density (LND) has previously been reported to reliably predict recurrence risk and survival in oral cavity squamous cell carcinoma (OSCC). This multicenter international study was designed to validate the concept of LND in OSCC.
The study included 4254 patients diagnosed as having OSCC. The median follow-up was 41 months. Five-year overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), locoregional control and distant metastasis rates were calculated using the Kaplan–Meier method. Lymph node density (number of positive lymph nodes/total number of excised lymph nodes) was subjected to multivariate analysis.
The OS was 49% for patients with LND⩽0.07 compared with 35% for patients with LND>0.07 ( P<0.001). Similarly, the DSS was 60% for patients with LND⩽0.07 compared with 41% for those with LND>0.07 ( P<0.001). Lymph node density reliably stratified patients according to their risk of failure within the individual N subgroups ( P=0.03). A modified TNM staging system based on LND ratio was consistently superior to the traditional system in estimating survival measures.