Survival in node-positive early oral squamous cell carcinoma following sentinel lymph node biopsy or elective neck dissection

OBJECTIVES: Investigate if choice of neck management by sentinel lymph node biopsy (SLNB) or elective lymph node dissection (ELND) affects disease specific (DSS) or overall survival (OS) in cT1-T2 N0 oral cancer patients subsequently diagnosed with occult metastasis (pN+). METHODS: Retrospective study of cT1-T2 N0 OSCC upstaged pathologically (pN+) by either SLNB or ELND at three major UK head and nek surgery centres between 2006 and 2021. Univariate and multivariate Cox proportional hazard regression analysed factors influencing survival. The most influential hazard ratios were selected for matched pair analysis of 4- and 6-variables. Cases were matched by a specifically designed algorithm. OS and DSS of matched-pairs were investigated by Kaplan-Meier survival analysis. RESULTS: Seventy-three pN+ patients were identified in the SLNB group and 153 pN+ patients in the ELND group. Matched-pair algorithm generated 69 matches across four variables (extranodal tumour extension (ENE), depth of invasion (DOI), perineural invasion (PNI) and the absence of associated dysplasia) and 70 matches at six variables (ENE, DOI, PNI and absence of associated dysplasia, LVI, non-cohesive invasive front). Matched-pair analysis of both 4 and 6 variables found no significant difference between pN+ SLNB and pN+ ELND for both 5-year DSS (71% vs. 61%, p = 0.718) and OS (71% vs. 58%, p = 0.322) CONCLUSIONS: There is no evidence to suggest the choice of neck management influences survival outcomes in early OSCC patients harbouring occult metastasis.