Sentinel lymph node biopsy for clinically N0 oral squamous cell carcinoma.

Abstract

5584 Background: Regionallymph node metastasis is an important prognostic factor in oral squamous cell carcinoma (OSCC). 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 case in a single-institution experience. Methods: 100 patients with cN0 OSCC underwent SLNB between 2001 and 2011, of which 95 were clinically T1 and T2. The primary site was tongue, gingiva, oral floor, buccal mucosa, and lip in 50%, 36%, 8%, 5%, 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. Results: SLNB was performed with RI and dye method (79%), only dye method (14%), or only RI method (7%). SLN was successfully identified with RI method (100%) and dye method (71%). The average number of SLN was 2.5 with dye method and 1.9 with RI method. The rate of SLN identified side was 84% in ipsilateral, 10% in bilateral, and 6% in contralateral. Fifteen of 100 patients (15%) had metastasis-positive SLN, and 3 patients was up-grade to stage III and others to stage IVA. Eight patients with negative SLN developed latent neck lymph node metastasis. The sensitivity, specificity, accuracy, and negative predictive value was 65% (15/23), 100% (77/77), 92% (92/100) and 91% (77/85). Disease specific survival rate for SLNB-negative patients were 98% (79/81), and for SLNB-positive patients were 73% (11/15), respectively. Conclusions: SLNB is a minimally invasive and highly reliable means of staging the cN0 neck for patients with OSCC. Patients with negative SLNB showed more excellent neck control rate and SLNB provides more accurate staging than elective neck dissection or wait and see.