Survival Significance of Number of Positive Lymph Nodes in Oral Squamous Cell Carcinoma Stratified by p16.

To analyze the significance of the number of positive lymph nodes in oral squamous cell carcinoma (SCC) stratified by p16. A total of 674 patients were retrospectively enrolled and divided into 4 groups based on their number of positive lymph nodes (0 vs. 1-2 vs. 3-4 vs. ≥5). The Kaplan-Meier method was used to calculate the disease-free survival (DFS) and disease-specific survival (DSS) rates. Cox model was used to evaluate the independent risk factor. p16 showed positivity in 85 patients with a rate of 12.6%. In patients with p16 negativity, the 5-year DFS rates were 52%, 39%, and 21% in patients with 0, 1-2, and 3-4 positive lymph nodes, respectively, in patients with ≥5 positive lymph nodes, all patients developed recurrence within 2 years after operation, the difference was significant; the 5-year DSS rates were 60, 38, and 18% in patients with 0, 1-2, and 3-4 positive lymph nodes, respectively, in patients with ≥5 positive lymph nodes, all patients died within 4-years after operation. The difference was significant. In p16 positivity patients, the 3-year DFS rates were 41% and 17% in patients with 0-2 and ≥3 positive lymph nodes, respectively, the difference was significant; the 3-year DSS rates were 84 and 46% in patients with 0-2 and ≥3 positive lymph nodes, the difference was significant. The number of positive lymph nodes is significantly associated with the survival in oral SCC, its survival effect is not affected by p16 status.