Clinical features and prognostic factors of extrathyroidal extension in differentiated thyroid carcinoma / 中华内分泌外科杂志

ABSTRACT

Objective:To investigate the risk factors related to extrathyroidal extension (ETE) of differentiated thyroid carcinoma (DTC) and the specific effects on the prognosis.Methods:The clinical data of 592 patients with newly diagnosed DTC admitted to our hospital from Jun. 2015 to Jun. 2016 were retrospectively analyzed. The data including the maximum tumor diameter and lymph node metastasis were collected, and the survival data were followed up. Chi-square test and Logistic regression were used to analyze the risk factors associated with ETE. Kaplan-Meier method and Cox proportional risk model were used to analyze the effect of ETE on disease-free survival.Results:There were 100 ETE of 592 DTC patients (16.9%) . Univariate analysis showed that the risk factors for ETE were the largest tumor diameter ≥2 cm, multiple lesions, and lymph node metastasis in the lateral cervical region ( P<0.01) . The follow-up time was 29 to 64 months, and the median follow-up time was 60 months. The 3-year and 5-year DFS rates of patients with DTC and ETE were 86.9% and 83.2% respectively, which were significantly lower than those of patients without ETE ( P<0.001) . Univariate analysis showed that ETE ( P<0.001) was a risk factor for postoperative recurrence in patients with DTC. Cox multivariate regression showed that ETE (HR 10.564, 95% CI 3.712-30.063, P<0.001) was an independent risk factor for postoperative recurrence in patients with DTC. Conclusions:DTC accompanied by ETE is associated with risk factors such as large tumor diameter and multiple lesions, which has a lower 5-year DFS. Patients with the above characteristics should consider the possibility of ETE before surgery, and focus on long-term follow-up after surgery.