Endocrine Abstracts

Objectives: Prognosis of differentiated thyroid carcinoma (DTC) is usually good, but even so a proportion of the patients develop recurrences and eventually die of the disease. The aim of this study was to analyze the clinical and histopathological features of patients with DTC in our center and to identify prognostic factors in this group of patients.

Patients and methods: We reviewed, retrospectively, 213 patients (184 females and 29 males, mean age 48.8 years, range 19–86) with DTC (192 papillary and 21 follicular carcinoma) who were treated in our hospital from 1992 up to 2012. Total thyroidectomy was performed in 186 patients (87.3%), bilateral near total thyroidectomy in nine of them (4.2%) and hemithyroidectomy in 18 patients (8.4%). Lymphadenectomy was carried out in 80 patients (37.5%). The mean follow-up period was 6.83 years (1–20 years) and the patients were ranked by the pTNM system. Survival probability was calculated using Kaplan–Meier analyses. Prognostic factors were analyzed using a univariate log rank test and a multivariate Cox regression analysis model.

Results: Fifteen patients (7.04%) had local or distant recurrences, which nine of them had locoregional metastases, the mean time to recurrence being 61.3 months. The 10 years overall survival rate for the entire group was 89%, with a mean survival time of 17.5 years. The factors affecting 10 years disease-free survival were T₄a, soft tissue invasion, lymph node metastasis and involvement of more than five nodes. The factors that better predicted the DTC recurrence in a multivariate analyses were nodal involvement (HR 4.86, CI 1.42–16.54, P 0.01) and soft tissue invasion (HR 4.49, CI 1.21–16.65, P 0.02). The only factor that affected overall survival was vascular invasion.

Conclusions: In our series, lymph node metastases and soft-tissue involvement were associated with an increased risk of recurrence while vascular invasion was the factor related to a higher risk of death.