Risk factors of central lymph node metastasis in cN0 papillary thyroid carcinoma: A study of 529 patients

BACKGROUND Lymph node metastasis in papillary thyroid carcinoma (PTC) is common; however, the need for prophylactic central lymph node dissection (CLND) in PTC is still controversial. The objective of this study was to investigate the risk factors of central lymph node metastasis (CLNM) in clinically lymph node-negative (cN0) PTC patients. MATERIAL AND METHODS A total of 529 cN0 PTC patients who underwent lobectomy plus isthmusectomy or total thyroidectomy with unilateral or bilateral CLND between 2010 and 2012 were enrolled in this study. Clinicopathologic risk factors for CLNM were studied using univariate and multivariate analysis. RESULTS CLNM was found in 238 (45.0%) cases. In univariate analysis, male sex, age <45 years, tumor size >2 cm, tumor located in the middle/lower third of lobe, and multifocality were significantly associated with CLNM (P<0.05); extrathyroid extension, Hashimoto's thyroiditis, and TSH value were not associated with CLNM. In multivariate analysis, tumor size >2 cm, age <45 years, multifocality, and tumor located in the middle/lower third of the lobe were independent predictors for CLNM. CONCLUSIONS Prophylactic CLND should be considered in cN0 PTC patients with the following risk factors: tumor size >2 cm, age <45 years, multifocality, or tumor located in the middle/lower third of the lobe. However, further long-term follow-up studies and multicenter research are needed to better understand these risk factors and the significance of prophylactic CLND.