Elective Neck Dissection Versus Therapeutic Neck Dissection in Clinically Node-Negative Early Stage Oral Cancer: A Meta-analysis of Randomized Controlled Trials.

Introduction: Oral squamous cell carcinoma (OSCC) is characterized by a high risk of cervical lymph node metastasis; however, it is still not clear whether patients with early stage OSCC with clinical N0 neck should undergo elective neck dissection (END) at the time of primary tumor removal, or they should undergo a conservative approach of observation (OBS), with therapeutic neck dissection at the time of lymph nodal recurrence. We conducted a meta-analysis of randomized controlled trials (RCTs) that compared these two approaches. Methods: PubMed and Scopus databases were searched for RCTs published in English language related to END and OBS in patients with early stage OSCC with clinical N0 neck. A meta-analysis was performed using random effects model with hazard ratio (HR) as the effect size for survival parameters and odds ratio (OR) as the effect size for lymph nodal recurrence. Results: A total of 7 RCTs, comprising 1250 patients were included in the meta-analysis. Results of the meta-analyses showed that as compared to OBS approach, END could significantly improve overall survival (HR 0.67; 95% CI 0.53, 0.86) and disease-free survival (HR 0.64; 95% CI 0.46, 0.89), and significantly reduce lymph nodal recurrence (OR 0.28; 95% CI 0.12, 0.66). After correcting for heterogeneity, the disease specific survival was also found to be improved by the END approach (HR 0.53; 95% CI 0.29, 0.98). Conclusion: The results of this meta-analysis suggest that elective neck dissection at the time of resection of the primary tumor not only leads to a reduced chance of nodal recurrence, but also confers a survival benefit in patients with clinically node-negative early stage oral cancer.