A meta-analysis of the randomized controlled trials on elective neck dissection versus therapeutic neck dissection in oral cavity cancers with clinically node-negative neck

There is still no consensus on the optimal treatment of the neck in oral cavity cancer patients with clinical N0 neck. The aim of this study was to assess a possible benefit of elective neck dissection in oral cancers with clinical N0 neck. A comprehensive search and systematic review of electronic databases was carried out for randomized trials comparing elective neck dissection to therapeutic neck dissection (observation) in oral cancer patients with clinical N0 neck. A meta-analysis of the studies which met our defined selection criteria was performed using disease-specific death as the primary outcome, and the relative risk (RR) of disease-specific death was calculated for each of the identified studies. Both fixed-effects (Mantel-Haenszel method) and random-effects models were applied to obtain a combined RR estimate, although between-study heterogeneity was not found to be significant as indicated by an I2 of 8.5% (p = 0.350). Four studies with a total of 283 patients met our inclusion criteria. The results of the meta-analysis showed that elective neck dissection reduced the risk of disease-specific death (fixed-effects model RR = 0.57, 95% CI 0.36-0.89, p = 0.014; random-effects model RR = 0.59, 95% CI 0.37-0.96, p = 0.034) compared to observation. This reduction in disease-specific death rate supports the need to perform elective neck dissection in oral cancers with clinical N0 neck.