Endocrine Abstracts

Background: The incidence of thyroid cancer is increasing worldwide. In Korea, the incidence of thyroid cancer increased from 1999 to 2011, but subsequently decreased from 2012 until recently. The most common type of thyroid cancer is papillary thyroid cancer (PTC). Although PTC has an excellent prognosis, a recurrence rate of 30% has been reported.

Methods: This study retrospectively reviewed 2,842 patients who underwent primary thyroidectomy for PTC by a single surgeon between March 2007 and December 2018. Patients with preoperative distant metastasis were excluded.

Results: Among the 2,842 patients, 39 patients (1.4%) experienced disease recurrence during a median follow-up period of 5.0 years (range, 0–12 years). According to univariate analysis, tumor size (> 1 cm), bilaterality, multifocality, extrathyroidal extension, lymphovascular invasion, perineural invasion, T stage (≥ T2), numbers of central and lateral neck lymph node (LN) metastases, stimulated thyroglobulin concentration, and radioactive iodine dose were associated with disease recurrence. According to a multivariate analysis, only the number of central neck LN metastases was associated with disease recurrence (odds ratio 1.144, 95% confidence interval 1.054–1.241, P = 0.001).

Conclusion: Patients with clinicopathologic characteristics related to disease recurrence specifically central neck LN metastasis should be followed up carefully.