Contralateral neck metastasis in lateralized cT3/4N0 oral squamous cell carcinoma.

Our goal was to investigate the pattern of contralateral lymphatic drainage (CLD) and contralateral neck failure (CNF) in cT3/4N0 oral cancer patients subjected to lymphoscintigraphy guided elective neck dissection (LSG-END) versus END. Patients were retrospectively enrolled and divided into two groups based on neck management. Pattern of CLD in LSG-END cohort was descriptively presented. Impact of LSG-END vs. END on CNF and overall survival was analyzed using Cox model. In total, 450 patients were included. In the LSG-END group, 54 patients exhibited CLD, resulting in an incidence of 23.5% and independently predicted by primary site, differentiation, tumor stage, and lymphovascular invasion. Contralateral levels I and II were the most involved site, and significantly influenced by primary site. In Cox model, patients treated with END had approximately double the risk of contralateral recurrence compared to those managed with LSG-END. Patients undergoing treatment with either END or LSG-END exhibited comparable OS rates. Among patients with cT3/4N0 oral cancer, CLD was observed in approximately one-quarter of the cohort. Although no additional overall survival advantage was identified, LSG-END proved to be more effective in controlling CNF compared to conventional END.