Sentinel lymph node biopsy versus elective neck dissection in management of the clinically negative (cN0) neck in patients with oral squamous cell carcinoma: A systematic review and meta-analysis

Oral squamous cell carcinoma (OSCC) is the most prevalent type of head and neck cancer, and lymph node metastasis is a crucial prognostic factor that has a direct correlation with the survival rate. The standard procedure for managing clinically negative (cN0) neck in OSCC patients is elective neck dissection (END), but it can lead to various complications that affect the patient's quality of life. Therefore, medical professionals are exploring the use of the sentinel lymph node biopsy (SLNB) to manage cN0 neck in OSCC patients. The aim of this systematic review and meta-analysis was to compare the overall survival (OS) and disease-free survival (DFS) of patients undergoing SLNB and END in the surgical management of early cN0 neck in OSCC patients. To conduct this study, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used to report the systematic reviews. The study included all comparative clinical studies, including randomized clinical trials (RCTs), clinical perspective studies, and retrospective studies that compared END to SLNB for early cN0 neck in OSCC patients. The hazard ratio (HR) and risk ratio (RR) with 95% confidence interval (CI) were calculated using comprehensive meta-analysis. The primary outcome variables were OS, DFS, and disease-specific survival (DSS). The secondary outcome variable was the nodal recurrence rate without local or distant metastasis. The GRADE system was used to assess the evidence's certainty. The meta-analysis included 12 clinical studies, comprising three RCTs and seven non-RCTs. The results showed no statistically significant difference between END and SLNB concerning OS (HR = 0.993, CI: 0.814 to 1.211, P = 0.947, low-quality evidence), DFS (HR = 0.705, CI: 0.408 to 1.29, P = 0.21, low-quality evidence), and nodal recurrence (RR = 1.028, CI: 0.969 to 1.090, P = 0.907, low-quality evidence). Additionally, SLNB was non-inferior to END regarding DSS (RR = 1.028, CI: 0.969 to 1.090, P = 0.907, low-quality evidence). In conclusion, this research affirms the safety and precision of SLNB as a means to stage cN0 OSCC patients, with outcomes that are comparable to END in terms of survival and nodal recurrence. Nevertheless, it's crucial to acknowledge that the quality of evidence in this study was relatively low. Therefore, additional RCTs comparing END to SLNB are warranted to validate these results and offer more robust guidance for managing cN0 OSCC patients.