Prophylactic Central Neck Dissection for Papillary Thyroid Carcinoma with Clinically Uninvolved Central Neck Lymph Nodes: A Systematic Review and Meta-analysis

Central neck dissection and total thyroidectomy are standard treatments for patients with papillary thyroid carcinoma (PTC) with clinically involved central nodes. However, prophylactic central neck dissection (pCND) in patients with clinically uninvolved cN0 has been beneficial in some studies but ineffective in others. We conducted a meta-analysis to evaluate the efficacy and safety of pCND in patients with central neck lymph nodes cN0 PTC. The PubMed, EMBASE, Cochrane Library, and Scopus databases and the ClinicalTrials.gov registry were electronically searched for studies published until September 2017. The meta-analysis was conducted to calculate the pooled effect size by using random-effects model. Treatment efficacies were measured by determining locoregional recurrence (LRR). Secondary outcomes included transient recurrent laryngeal nerve (RLN) injury, permanent RLN injury, transient hypocalcemia, and permanent hypocalcemia. Twenty-three retrospective and prospective cohort studies involving 18,376 patients were reviewed. Patients who underwent pCND had significantly lower LRR (odds ratio [OR] 0.65; 95% confidence interval [CI] 0.48-0.88) but significantly higher incidence rates of transient RLN injury (OR 2.03; 95% CI 1.32-3.13), transient hypocalcemia (OR 2.23; 95% CI 1.84-2.70), and permanent hypocalcemia (OR 2.22; 95% CI 1.58-3.13) than that of no pCND group. Compared with no pCND, pCND significantly reduces LRR but is accompanied by numerous adverse effects. The clinical decision should be made after the shared decision-making process of clinicians and patients.