Recent changes in the clinical outcome of papillary thyroid carcinoma with cervical lymph node metastasis

Abstract

Context: The prognosis of papillary thyroid cancer (PTC) with cervical lymph node (LN) metastasis has changed with increased detection of subclinical metastatic LNs. The number and size of metastatic LNs were proposed as new prognostic factors in PTC with cervical LN metastasis (N1). Objective: The objective of the study was to evaluate changes in N1 PTC characteristics and clinical outcome over time and to confirm the prognostic value of the number and size of metastatic LNs. Design and Patients: This study included 1815 N1 PTC patients diagnosed between 1997 and 2011. Patients were classified into three risk groups according to the number and size of metastatic LNs: very low risk, five or fewer and 0.2 cm or less; low risk, five or fewer and 0.2 cm or greater; and high risk, more than five. MainOutcomeMeasures: Response to initial therapyanddisease-free survival (DFS)wasmeasured. Results: Metastatic LNs became smaller, and the ratio of metastatic LNs, which represents the extent of LN involvement and the completeness of surgery, decreased significantly over time. The proportion of patients with excellent response significantly increased from 33% to 67% over time (P