Despite advances in early detection, diagnosis, and treatment of oral squamous cell carcinoma (OSCC), the survival for patients with early stage OSCC remains at 80% for the past 30 years. Nodal status is still the most significant prognostic factor of OSCC. Therefore, early detection of the cervical lymph nodes metastasis is expected to further improve survival. Sentinel lymph node biopsy (SLNB) is a widely accepted procedure in various human malignancies. In clinically N0 (cN0) OSCC cases, SLNB has received considerable attention for its role in deciding whether to perform neck dissection. In this study, we assessed the efficiency of SLNB for cN0 OSCC in a single-institution experience.
A total of 135 patients with cN0 OSCC underwent SLNB between 2001 and 2016, of which 128 were clinically T1 and T2. The primary site was tongue, gingiva, oral floor, buccal mucosa, and lip in 49%, 36%, 7%, 6%, and 1%, respectively. The location of sentinel lymph node (SLN) was determined by radioisotope (RI) method with preoperative lymphoscintigraphy and intraoperative use of a handheld gamma probe and/or dye method and evaluated by histopathological examination and genetic analysis.
SLNB was performed with RI method (90%) or dye method (10%). SLNs were successfully identified with RI method (100%) and dye method (70%). The average number of SLN/case was 1.9 with RI method and 2.3 with dye method. The rate of SLN identified side was 85% in ipsilateral, 9% in bilateral, and 6% in contralateral. Twenty two of 135 patients (16%) had metastasis-positive SLN. Thirteen patients with negative SLN developed the latent neck lymph node metastasis. The sensitivity, specificity, and accuracy was 62.9% (22/35), 100% (100/100), and 90.4% (122/135), respectively. Three-year overall survival rate for SLNB-negative patients was 95.6% (108/113).
SLNB is a minimally invasive and highly reliable method staging the cN0 for patients with OSCC. Patients with negative SLNB showed more excellent neck control rate and the SLNB provides more accurate staging than elective neck dissection or wait and see.
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