The Prognostic Significance of the Metastatic Lymph Node Ratio in Patients with Papillary Thyroid Carcinoma / 대한내분비외과학회지

ABSTRACT

PURPOSE: Metastatic lymph node ratio (MLNR) is known as an important prognostic factor in many solid carcinomas; however, the role of MLNR in papillary thyroid carcinoma (PTC) is unclear. The purpose of this study was to determine whether MLNR has prognostic significance for recurrence in patients with pathological N1a PTC. METHODS: A retrospective analysis was conducted of 1,198 patients with PTC who underwent total thyroidectomy with central neck dissection between 2006 and 2011. Only patients with central lymph node metastasis were included in this study. Patients with lateral neck lymph node metastasis or extrathyroidal involvement were excluded. Finally, this study included 282 patients with N1a patients. MLNR was defined as the number of metastatic lymph nodes divided by the number of removed lymph nodes. RESULTS: Median age was 47.3 years (17~73 years). There were 209 female patients and 41 male patients, respectively. Median follow-up period was 53 months (36~114 months). Median value of MLNR was 0.36 (0.04~1.000). Of 250 patients, 20 patients (8.0%) developed recurrent disease. MLNR independently predicted PTC recurrence (odds ratio [OR], 6.385; 95% confidence interval [CI], 2.523-16.158; P 0.47 should be monitored closely for recurrence.