Nodal Metastasis in Surgically Treated Oral Cavity Squamous Cell Carcinoma

Introduction: Management of the neck in oral cavity squamous cell carcinoma (OCSCC) is essential to oncologic control and survival. The rates of lymph node metastasis (LNM) vary based on oral cavity tumor site and stage and influence treatment decisions. The aim of this paper was to describe clinical LNM for different tumor subsites and stages of surgically managed OCSCC. Methods: We conducted a retrospective analysis of 25,846 surgically managed OCSCC patients from the National Cancer Database (NCDB) stratified by tumor subsite and clinical T-stage. For cN + patients, rates of pathologic LNM and absence of pathologic LNM were determined. For cN0 patients, outcomes included the rates of elective neck dissection (END) and occult LNM and predictors of occult LNM determined by a multivariable logistic regression model. Results: A total of 25,846 patients (59.1% male, mean age 61.9 years) met inclusion criteria with primary tumor sites including oral tongue (50.8%), floor of mouth (21.2%), lower alveolus (7.6%), buccal mucosa (6.7%), retromolar area (4.9%), upper alveolus (3.6%), hard palate (2.7%), and mucosal lip (2.5%). Among all sites, clinical N+ rates increased with T-stage (8.9% T1, 28.0% T2, 51.6% T3, 52.5% T4); these trends were preserved across subsites. Among patients with cN + disease, the overall rate of concordant positive pathologic LNM was 80.1% and the rate of discordant negative pathologic LNM was 19.6%, which varied based on tumor site and stage. In the overall cohort of cN0 patients, 59.9% received END, and the percentage of patients receiving END increased with higher tumor stage. Occult LNM among those cN0 was found in 25.1% of END cases, with the highest rates in retromolar (28.8%) and oral tongue (27.5%) tumors. Multivariable regression demonstrated significantly increased rates of occult LNM for higher T stage (T2 OR: 2.1 [1.9-2.4]; T3 OR: 3.0 [2.5-3.7]; T4 OR: 2.7 [2.2-3.2]), positive margins (OR: 1.4 [1.2-1.7]), and positive lymphovascular invasion (OR: 5.1 [4.4-5.8]). Conclusions: Management of the neck in OCSCC should be tailored based on primary tumor factors and considered for early-stage tumors.