Elective Neck Dissection Versus Wait-and-Watch Policy for Oral Cavity Squamous Cell Carcinoma in Early Stage: A Systematic Review and Meta-Analysis Based on Survival Data

Purpose: Whether elective neck dissection (END) should be adopted for patients with clinically early-stage (cT1-2N0M0) oral cavity squamous cell carcinoma (OCSCC) remains debated. The aim of this systematic review was to compare the survival benefit of END with that of the wait-and-watch policy (WW) for patients with early-stage OCSCC based on survival data. Materials and Methods: According to the inclusion criteria, an exhaustive search for eligible studies was conducted. The study inclusion and data extraction were performed by 2 reviewers independently. The risk of bias was assessed in duplicate using the Risk Of Bias In Nonrandomized Studies of Interventions instrument. The hazard ratio (HR) of the time-to-event data was extracted or estimated. RevMan 5.3 and STATA 15.1 were adopted for data synthesis. Results: Of the 35 studies that were included, only 5 were assessed as having a low risk of bias. Results of the meta-analyses showed END could significantly decrease neck recurrence (relative risk = 0.45; confidence interval [CI], 0.35-0.59; P < .00001) and improve disease-free survival (HR = 0.55; CI, 0.42-0.71; P < .00001), overall survival (HR = 0.75; CI, 0.64-0.86; P < .0001), and disease-specific survival (HR = 0.76; CI, 0.61-0.94; P = .01) compared with WW for patients with cT1-2N0. The subgroup analysis showed that END could decrease neck recurrence (P < .00001) and improve disease-free survival (P = .001) for patients with early-stage tongue cancer and that supraomohyoid neck dissection could decrease neck recurrence (P = .02). For patients with cT1N0, END could significantly decrease the proportion with neck recurrence (P = .0008) and improve disease-free survival (P = .0003), but the difference between overall survival and disease-specific survival did not achieve significance. Conclusions: END can decrease recurrence and improve survival time for patients with early-stage OCSCC. More high-quality studies are needed to make a solid conclusion, especially for patients with cT1N0M0. (C) 2019 American Association of Oral and Maxillofacial Surgeons