SURGICAL TREATMENT OF LOCALLY ADVANCED WELL DIFFERENTIATED THYROID CARCINOMA

AIMS: We aimed to better define the most appropriate therapeutic protocol for this type of tumor. BACKGROUND: The incidence of well-differentiated thyroid carcinoma is rising and the mortality from the disease remains low for patients with early disease. Nevertheless, the survival of patients with advanced disease has not improved during the last four decades and a controversy still exists in the literature regarding the optimal treatment in patients with locally advanced (T4) differentiated thyroid carcinoma. METHODS: Meta-analysis of the literature and our institutional experience, in treating patients with advanced papillary/follicular thyroid carcinoma. The main outcome measures were overall survival (OS) and disease-specific survival (DSS). RESULTS: The study group consisted of 38 patients with locally advanced thyroid carcinoma (T4). Regional spread to nodal metastases was present in 25 (65.7%) patients. Tracheal invasion was diagnosed in 29 (76.3%), of those 10 (26.3%) patients had airway obstruction. Recurrent laryngeal nerve (RLN) paralysis was revealed with clinical evidence during diagnosis in 23 (60.5%) patients. The 5-years OS was 66% and DSS was 87%. Multivariate analysis of outcome showed that undifferentiated carcinoma foci and vocal cord paralysis were associated with significantly reduced 5-years OS, and vocal cord paralysis was the only independent prognostic variable for DSS. Male gender and adjuvant radioactive iodine treatment were significant prognostic variables for disease free survival but not OS or DSS. CONCLUSIONS: Surgical resection remains the mainstay of treatment for locally advanced differentiated thyroid cancers. Foci of poorly differentiated cells, vocal cord paralysis and male gender are associated with poor prognosis. Radioactive iodine treatment improved local control but did not not affect OS. These patients should be managed by a multidisciplinary team in university centers specializing in treating complicated cancer patients.