Elective Neck Dissection vs Observation in Early-Stage Squamous Cell Carcinoma of the Oral Tongue With No Clinically Apparent Lymph Node Metastasis in the Neck A Systematic Review and Meta-analysis

IMPORTANCE The elective management of no clinical or radiologic evidence of lymph node metastasis in the neck (cN0) in early stage T1-T2 oral tongue squamous cell carcinoma (OTSCC) has been the subject of much debate during the past 3 decades and continues to be controversial. OBJECTIVE To systematically review the literature and carry out ameta-analysis of studies that compared elective neck dissection (END) with observation in patients with early-stage T1-T2 OTSCC and cN0 neck. DATA SOURCES The MEDLINE, Scopus, Google scholar, and Cochrane databases were systematically searched for articles published between January 1, 1970, and June 1, 2015. Search terms used were squamous cell carcinoma, oral tongue, mobile tongue, T1, T2, early stage, elective neck dissection, no neck treatment, observation, wait and watch, node-negative neck, and N0 neck. STUDY SELECTION Controlled clinical trials, prospective and retrospective cohorts, case-control studies, and case series that compared END with observation in patients with early-stage T1-T2 OTSCC who had no clinical or radiologic evidence of lymph node metastasis to the neck were eligible for inclusion in this meta-analysis. All patients included had a histopathologic diagnosis of SCC and at least 6 months of follow-up. Regional (neck) nodal recurrence, overall survival (OS), and disease-specific survival (DSS) were tested. DATA EXTRACTION AND SYNTHESIS Four researchers independently extracted information on population characteristics, outcomes of interest, and study design. Discrepancies were resolved by consensus. Fixed effects were used to determine hazard ratios (HRs) and odds ratio (ORs) were used for studies including samples without substantial heterogeneity; random effects were evaluated for samples with significant heterogeneity. RESULTS A total of 20 retrospective and 3 prospective randomized studies that met the inclusion criteria, with a total of 3244 patients, were included in the meta-analysis The results showed that END significantly reduced risk of regional recurrence (random-effects model: OR, 0.32; 95% CI, 0.22-0.46; P < .001) and improved DSS (fixed-effects model: HR, 0.49; 95% CI, 0.33-0.72; P < .001) compared with management by observation. However, END did not significantly improve OS (random-effects model: HR, 0.71; 95% CI, 0.41-1.22; P = .21). CONCLUSIONS AND RELEVANCE The findings of this systematic review and meta-analysis indicate that END can significantly reduce the rate of regional nodal recurrence and improve DSS in patients with cT1T2N0 OTSCC.