Therapeutic lateral neck dissection in well-differentiated thyroid cancer : analysis on factors predicting distribution of positive nodes and prognosis

Background: Neck dissection is considered the treatment of choice in patients with lateral neck metastases from well-differentiated thyroid cancer. Methods: A multicenter, retrospective review of patients who underwent therapeutic lateral neck dissection for well-differentiated thyroid carcinoma was carried out. Results: The study included a total of 405 lateral neck dissections performed in 352 patients; 197 women (56%) and 155 men (44%). When considering ipsilateral neck metastases, levels IIa, IIb, III, IV, Va, Vb, and V (not otherwise specified) were involved in 42%, 6%, 73%, 67%, 11%, 31%, and 35% of cases, respectively. Five-year and 10-year overall survival (OS) were 93% and 81%, respectively. Age >55 years, pathologic T (pT)4 category, tumor diameter >4 cm, aggressive variants of well-differentiated thyroid carcinoma, endovascular invasion, and number of positive nodes >5 turned out to be the most important prognostic factors. Conclusion: Neck dissection is a valid treatment option in the presence of neck metastasis from well-differentiated thyroid carcinoma. Levels IIa, III, IV, and Vb should always be removed.