The Prognostic Value of Lymph Node Burden in Oral Cavity Cancer: Systematic Review and Meta-Analysis

Objectives Lymph node burden has been proposed to estimate the cumulative adverse effect of nodal metastasis. In this study, a meta-analysis was conducted to evaluate the prognostic value of lymph node burden in oral cavity squamous cell carcinoma. Study Designs Systemic review and meta-analysis. Methods PubMed, EMBASE and the Cochrane Library as well as manual searches were performed until April 2020. The adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of overall survival, disease-specific survival, and disease-free survival were extracted and pooled. Results Eleven included studies were published between 2009 and 2019. The cumulative number of patients was 20,607 (range 35-14,554). Extranodal extension was adjusted or evaluated in all of the studies. The meta-analysis indicated that a higher lymph node burden was significantly related to worse overall survival (HR 2.62, 95% CI 2.12-3.25), worse disease-specific survival (HR 3.14, 95% CI 1.85-5.33) and worse disease-free survival (HR 2.30, 95% CI 1.62-3.26). The highest hazard ratio was observed when the cutoff value was 3 for overall survival, 3 for disease-specific survival, and 4 for disease-free survival. The hazard ratio showed an upward trend before the cutoff value of 3 but no significant incremental change when the cutoff exceeded 3. Conclusions In oral squamous cell carcinoma, lymph node burden is an independent prognosticator for survival outcomes. However, more prospective or high-quality studies are required to determine the optimal cutoff. Level of Evidence NA Laryngoscope, 2021