Sentinel node biopsy in early oral squamous cell carcinomas: Long-term follow-up and nodal failure analysis

Objectives: Evaluate the reliability of sentinel node biopsy (SNB) in T1/T2 cN0 oral squamous cell carcinoma (OSCC), and compare recurrence-free time (RFT) and overall survival (OS) between patients undergoing SNB and neck dissection (ND). Patients and methods: Patients with T1/T2 cN0 OSCC underwent SNB followed by systematic ND in the first cohort and SNB followed by selective ND in case of positive sentinel nodes (SN) in the second cohort. Results: A total of 229 patients were followed (first cohort 50, second cohort 179). SNs were successfully detected in 93.9% (215/229) of cases. Median follow-up was 5.6 years. Recurrence occurred in 38/215 patients, with isolated nodal recurrence in 18/215 patients. At 5 years, the rate of recurrence-free patients was 80.0% and the rate of patients without isolated nodal recurrence was 90.4%. Negative predictive value of SNB was 92.7%. No statistically significant difference was observed between the two groups regarding RFT and OS. In 83% (10/12) of ipsilateral isolated nodal recurrences, primary tumor was located in anterior part of oral cavity. Only 43% (3/7) of SN+ patients with nodal recurrence were eligible for salvage surgery, compared to 91% (10/11) of SN-patients. SNB resulted in fewer complications than ND (8% vs 28%, p < 0.0001). Conclusion: SNB is a reliable staging tool for T1/T2 cN0 OSCC, without adverse effect on patient survival and fewer complications. No late recurrences occurred in long-term follow-up. Close follow-up is mandatory for SN+ patients, who are at higher risk of nodal recurrence and have worse prognosis.