Factors Associated with Metastatic Lymph Node Ratio, Extranodal Extension in the Central Compartment Node-Positive Papillary Thyroid Carcinoma

Received February 12, 2015 Revised March 27, 2015 Accepted March 31, 2015 Address for correspondence Kang Dae Lee, MD, PhD Department of OtolaryngologyHead and Neck Surgery, Kosin University College of Medicine, 262 Gamcheon-ro, Seo-gu, Busan 602-702, Korea Tel +82-51-990-6470 Fax +82-51-245-8539 E-mail kdlee59@gmail.com Background and ObjectivesZZLymph node (LN) metastasis occurs in 30-80% of patients presenting for initial treatment of papillary thyroid carcinoma (PTC). The presence of LN metastasis is an independent risk factor for recurrence, which can add significant treatment morbidity. The LN ratio (LNR) and extranodal extension (ENE) have been shown to be important prognostic factors in PTC. The purpose of this study was to assess the characteristic features of LNR and ENE. Subjects and MethodZZWe undertook a retrospective study of 411 patients treated between January, 2011 and December, 2013 for central compartment node-positive PTC by thyroidectomy and central compartment neck dissection (CCND) at our institution. We compared various clinicopathologic parameters such as age, gender, tumor size, multifocality, bilaterality, local invasion, extrathyroidal extension and aggressive variants between LNR and ENE. ResultsZZThe significant associated factors for high LNR (defined as higher than 0.5) in multivariate analysis were gender (p=0.001, odds ratio=2.285) and multifocality (p=0.027, odds ratio=2.092). On the other hand, the significant associated factors for ENE in multivariate analysis were primary tumor size (p=0.023, odds ratio=1.965) and local invasion (p=0.043, odds ratio=1.870). ConclusionZZBeing male, multifocality, large primary tumor size (defined as larger than 1 cm) and local invasion were revealed as associated factors for LNR and ENE. Therefore, elective CCND should be considered for patients with PTC, for whom a thorough investigation of associative factors should be made before surgery. Korean J Otorhinolaryngol-Head Neck Surg 2015;58(7):475-80