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

ABSTRACT

BACKGROUND AND OBJECTIVES: Lymph 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 METHOD: We 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. RESULTS: The 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). CONCLUSION: Being 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.