Lymph Node Yield Per Neck Level as a Predictor of Recurrence in Oral Tongue Squamous Cell Carcinoma: a Retrospective Observational Study

The oral tongue is a common location for squamous cell carcinoma (SCC) and behaves more aggressively. Lymph node yield(LNY) is a robust independent prognostic factor in oral SCC. In this study, we attempt to determine the prognostic significance of LNY per neck node level for oral tongue SCC. This retrospective observational study includes 302 patients with oral tongue SCC who were operated in our unit between 2017 and 2022. Relevant data were collected, and patients followed up for at least 24 months. LNY per level was calculated and correlated with recurrence and overall survival. A total of 344 neck dissections were performed on 302 patients. On average, 36 nodes (36.05 +/- 15.02) were harvested per neck dissection. The maximum yield was found in level IIa, 6.72 (6-10), irrespective of pathological node positivity. On multivariate analysis, a higher LNY at level IIa significantly correlated with recurrence, along with other factors. We found that LNY of 10 or more nodes from level II might be a more sensitive predictor of recurrence than overall LNY per neck dissection. This could be because level II nodes receive a majority of lymphatic drainage from the oral tongue. Total LNY may be impacted by yield at other levels and may lull the surgeon into a false sense of security, when clearance of the most crucial nodal basin at level II remains suboptimal.