Elective Neck Dissection in cT1‐4 N0M0 Submandibular Gland Cancer

OBJECTIVE: To investigate occult nodal metastasis (ONM) and overall survival (OS) in patients undergoing elective neck dissection (END) for clinically node-negative submandibular gland cancer (SMGC). METHODS: The 2006 to 2018 National Cancer Database was retrospectively reviewed for patients with cT1-4 N0M0 SMGC undergoing surgical resection. Linear, binary logistic, Kaplan-Meier, and Cox proportional hazards regression models were implemented. RESULTS: A high proportion of patients were female (N = 710, 54.6%) and White (N = 1059, 82.5%) with adenoid cystic carcinoma histology (N = 567, 43.6%) classified as cT1 (N = 545, 41.9%). A minority of patients (N = 255, 19.6%) underwent END. Academic/research reporting facility, high grade, cT3, and cT4 classification were associated with higher odds of undergoing END; Medicare insurance was associated with lower odds (p < 0.05). ONM was identified in 63 (24.7%) patients undergoing END. The rate of ONM increased with cT classification (13.2% in cT1, 27.9% in cT2, 22.0% in cT3, and 50.0% in cT4) and grade (6.5% in well-differentiated, 9.5% in moderately differentiated, and 40.3% in poorly differentiated). END was not associated with OS (hazard ratio [HR] 1.11, 95% confidence interval [CI] 0.84-1.46, p = 0.461). However, ONM was associated with worse OS (HR 3.69, 95% CI, 2.25-6.05, p < 0.001); 5-year OS for patients without and with ONM was 83% and 50%, respectively (p < 0.001). CONCLUSION: END is performed frequently in SMGC but is not associated with OS. Although the rate of ONM approaches 25%, these findings suggest that END should not be routinely performed for prognostic purposes alone, especially in the absence of adverse features.