Impact of different categories of intermediate risk factors on the recurrence of papillary thyroid carcinoma: a retrospective cohort study.

Abstract

Data regarding the long-term recurrence in patients with intermediate-risk papillary thyroid carcinoma (PTC) are limited. The aim of this study was to assess the impact of primary tumor-related risk factors and lymph node (LN)-only risk factors on recurrence-free survival (RFS) in patients with intermediate-risk PTC. Patients with PTC who received initial treatment at our institution between 2010 and 2016 were retrospectively reviewed. A total of 799 intermediate-risk PTC patients were included and further categorized into subgroups according to the different categories of intermediate risk factors. The RFS rates of these subgroups were investigated and compared. Structural recurrence developed in 11 patients (1.4%) of the whole cohort during a median follow-up duration of 96 months. There were no significant differences in RFS between the primary tumor-only risk group and the LN-only risk group, while the combined group of primary tumor risk factors and LN risk factor (metastatic LNs >5) was associated with a worse RFS rate. In the matched-pair analysis, no significant difference in RFS was found between patients who underwent thyroid lobectomy (TL) and those who underwent total thyroidectomy (TT) (6-year RFS: 99.6% vs. 98.8%, P = 0.316) during a median follow-up duration of 100 months. Intermediate-risk PTC patients who underwent TL had a comparable RFS to those who underwent TT. The combination of primary tumor risk factors and LN risk factor (metastatic LNs >5) may be a useful tool for predicting the risk of long-term structural recurrence in patients with intermediate-risk PTC.