Sentinel lymph node biopsy for early oral cancer - accuracy and considerations in patient selection

Sentinel lymph node biopsy (SLNB) for staging oral squamous cell carcinoma (OSCC) patients presenting with early (T1 and T2 N0) disease in preference to elective neck dissection (END) remains controversial worldwide. A retrospective analysis of 145 patients who underwent sentinel lymph node biopsy for a previously untreated early oral cancer between 2010 and 2020 was performed. The primary outcome measures were predictors of occult metastases, accuracy of SLNB and disease specific plus overall survival. The negative predictive value, the false negative rate, and sensitivity for SLNB were 97%, 7.8%, and 92%, respectively. Depth of invasion (DOI) was a significant predictor of N status, overall survival, and disease specific survival. There was a significant difference in the incidence of the neck node metastasis in patients with DOI <5mm compared to those with DOI >5mm. For tumours >5mm there was a moderate to good correlation between radiological depth on contrast enhanced computed tomography (CECT) and histopathological DOI. Preoperative estimation of DOI may be a useful tool in the counselling of patients in the selection of either SLNB or END for N staging purposes in early OSCC.