Systematic review and meta-analysis of randomized controlled trials comparing elective neck dissection versus sentinel lymph node biopsy in early-stage clinically node-negative oral and/or oropharyngeal squamous cell carcinoma: Evidence-base for practice and implications for research

•Management of node-negative neck in early-stage oral cancer has been debatable.•Nearly 20-30% of such patients harbour occult metastases in draining lymph nodes.•The N0 neck is usually addressed with elective neck dissection or watchful waiting.•Sentinel lymph node biopsy is an intermediate approach between these two strategies.•Sentinel node biopsy is oncologically non-inferior to elective neck dissection. Management of clinically node-negative (N0) neck in early-stage (T1-T2) oral and/or oropharyngeal squamous cell carcinoma (OOSCC) has been controversial. The purpose of this systematic review and meta-analysis was to compare sentinel lymph node biopsy (SLNB) with elective neck dissection (END) in early-stage OOSCC. Studies comparing SLNB versus END in early-stage clinically node-negative OOSCC were identified using validated search strategy. To be considered eligible, trials had to include patients with early-stage, clinically node-negative OOSCC who had been randomly assigned to either SLNB or END. Primary outcome of interest was overall survival (OS), while secondary outcomes included isolated neck nodal recurrence (NNR), loco-regional recurrence (LRR), and neck-shoulder function. Outcome data was pooled using random-effects model and reported as hazard ratio (HR) or risk ratio (RR) with 95% confidence interval (CI). Any p-value