Efficacy of Elective Neck Dissection in T1/T2N0M0 Oral Tongue Squamous Cell Carcinoma

Abstract

Objective/Hypothesis The aim of this population-based study is to analyze the survival benefits of elective neck dissection (END) over neck observation in T1/T2N0M0 oral tongue squamous cell carcinoma (OT-SCC) cases. Study Design Retrospective administrative database analysis. Subjects and Methods The SEER database (Surveillance, Epidemiology, and End Results) was queried for patients diagnosed with T1/T2N0M0 OT-SCC from 1998 to 2011. Data included patient demographics, initial treatment, and survival outcomes. The Kaplan-Meier model and the Cox proportional hazards model were utilized for survival analysis. Results Out of 7010 T1/T2N0M0 cases, END was performed in 1770 T1 and 950 T2 cases, and the neck was observed in 3278 T1 and 1001 T2 cases. Significantly poorer 5-year disease-specific survival (DSS) rates were noted for the neck observation group when compared with the END group for tumors with moderately differentiated (72.1% vs 86%, P < .0001) and poorly differentiated or undifferentiated (55.6% vs 71.5%, P = .0001) histologic grades. No significant survival benefit was seen between the END group and the neck observation group when tumor size was <1 cm, regardless of histology grade. However, those with tumors >1 cm had a significantly better 5-year DSS with END, except for the well-differentiated tumor cohort, which showed improved survival only when the tumors were >2 cm (5-year DSS: END vs neck observation, 83.5% vs 65.7%, P = .0002). Conclusion END improves DSS versus neck observation in T1/T2N0M0 OT-SCC patients with moderately differentiated, poorly differentiated, or undifferentiated histologic grade tumors >1 cm. Those with well-differentiated tumors benefited from END only when tumor size was >2 cm.