Risk Factors for Distant Metastasis in Patients with Follicular Thyroid Carcinoma / 대한내분비외과학회지

ABSTRACT

PURPOSE: The major issue of follicular thyroid carcinoma (FTC) diagnosed after hemithyroidectomy is whether to undergo further treatments. The aim of this study is to examine the clinico-pathological characteristics of FTC and to evaluate the risk factors for distant metastasis. METHODS: From 1993 to 2010, 274 patients underwent initial thyroid surgery and were subsequently diagnosed as FTC. After review of the histological sections by an experienced pathologist, 211 patients were confirmed as FTC and were enrolled in this study. Clinicopathological features were compared based on the presence or absence of distant metastases, and the risk factors for distant metastases and distant metastases-free survival (DMFS) rates were analyzed. RESULTS: The patients included 39 males (18.5%) and 172 females (81.5%), with a mean age of 44.0±14.5 years. The median follow-up period was 99.5 months (range, 13.0~222.0). Distant metastases were detected in 23 patients (10.9%), including 15 synchronous distant metastases and 8 metachronous distant metastases. In multivariate analysis, age ≥45 years, widely invasive FTC, tumor size ≥4.3 cm, and vascular invasion were independent risk factors for distant metastasis. DMFS rates in patients with these risk factors were significantly poorer than those in patients without these risk factors. CONCLUSION: Older age, aggressive histological classification, larger tumor size, and vascular invasion were independent risk factors for distant metastasis. FTC patients with these risk factors may be candidates for further treatments after diagnostic thyroid hemithyroidectomy.