Locally unresectable differentiated thyroid cancer: outcomes and perspectives.

PURPOSE: Differentiated thyroid cancer (DTC) patients with an unresectable primary tumor cannot benefit from curative surgery, and radioiodine treatment for locoregional and distant disease is not possible with the thyroid gland still in place. Due to local invasion, these patients cannot be included in clinical trials, so that treatment options are limited. The aim of this study was to describe the characteristics and the prognosis of patients with these locally unresectable DTC. PATIENTS AND METHODS: A retrospective and multicentric analysis of consecutive cases of unresectable DTC diagnosed between 2000 and 2015 was performed. RESULTS: The study population consisted in 22 patients, 13 females (59%); median age: 77 years (range: 52-91). Thyroid tumors were papillary in six, follicular in seven, Hürthle cell in one and poorly differentiated in eight patients. Patients were treated with external beam radiation therapy (EBRT) (57%), locoregional therapy of distant metastases (41%), cytotoxic chemotherapy (38%) and tyrosine kinase inhibitors (TKIs) (33%). TKI treatment resulted in median disease control duration of 7 months with a grade 3-4 toxicity rate of 44%. Only one patient had a total thyroidectomy after neo-adjuvant EBRT. The 1, 3 and 5-year cumulative survival rate was 81%, 27.7% and 21.5%, respectively. The cause of death was DTC in 11 cases (local progression in 7), and to other causes in 7 cases; no patient died from treatment toxicity. CONCLUSIONS: Clinical trials and approved treatments are lacking for unresectable DTC. TKI treatment may allow prolonged disease control with acceptable toxicity.

Over ten years of single-institution experience in percutaneous image-guided treatment of bone metastases from differentiated thyroid cancer.

OBJECTIVE: Percutaneous image-guided treatments (PIGT) are performed by interventional radiologists with a minimally invasive approach. Currently, very little published data on their outcomes are available and conclusions regarding their application are cautious. The aim of the present study was to review our experience in PIGT of bone metastases from thyroid cancer. MATERIALS AND METHODS: Institutional databases were reviewed to identify patients with differentiated thyroid cancer and bone metastases who received PIGT between October 2001 and April 2014. Complications, local evolution of the treated lesions, and overall survival (OS) were investigated. RESULTS: Twenty-five patients (12 male, 13 female) underwent 49 PIGT sessions consisting of cementoplasty (77.5%), cryoablation (14.3%) or radiofrequency ablation (8.2%). Most of the treated lesions (50/54, 92.6%) were symptomatic at the time of PIGT. Median follow-up after PIGT was 4.6 years. Local complete remission rate was 55.6%. Two complications (one major and one minor) were noted, but none of these were consistent with fractures or nervous system injuries. OS after PIGT was 71.6%, 66.8% and 60.1% at 1, 2 and 3 years, respectively. A difference in survival was observed between patients with metastatic bone involvement only at the time of first PIGT compared to those with multi-organ involvement (P = 0.03). CONCLUSIONS: Patients with bone metastases from differentiated thyroid cancer may benefit from PIGT. Although patients are usually referred for PIGT due to their symptomatic status, a more relevant "curative" role may exist for PIGT. Further prospective studies are needed to confirm this perception.

Local treatment of metastases from differentiated thyroid cancer.

OBJECTIVES: To study the various local treatments available for thyroid cancer metastases, investigate techniques and assess their advantages and limitations and roles in the overall treatment strategy for metastatic disease. RESULTS: We investigated metastases surgery, external radiation therapy, embolization, chemoembolization, cementoplasty, radiofrequency ablation and cryotherapy, describing techniques, advantages and drawbacks and possible complications. Indications were reviewed according to metastases location, and the roles of the various techniques are discussed in the overall treatment strategy for thyroid cancer metastases. Despite the advent of new targeted therapies, local treatment still has an important role to play: either palliative or, in oligometastatic involvement, curative. Even in extensive disease, it may allow postponement of tyrosine kinase inhibitor therapy, which, once initiated, has to be continued life-long, is expensive and is not free of side-effects.