Recurrent Differentiated Thyroid Cancer: The Current Treatment Options

SIMPLE SUMMARY: The most appropriate treatment for local/regional recurrent differentiated thyroid cancers (DTC) is surgical excision if feasible, followed by adjuvant radioiodine administration. However, depending on the location or extent of the recurrence, surgical excision may not be possible, thus creating a need for alternative therapeutic interventions to maintain the otherwise excellent prognosis for this disease. In light of the increased incidence of this disease and the plethora of available systemic options, a detailed knowledge of the available treatment options is essential for successful management of recurrent DTC. ABSTRACT: Differentiated thyroid carcinomas (DTC) have an excellent prognosis, but this is sometimes overshadowed by tumor recurrences following initial treatment (approximately 15% of cases during follow-up), due to unrecognized disease extent at initial diagnosis or a more aggressive tumor biology, which are the usual risk factors. The possible sites of recurrence are local, regional, or distant. Local and regional recurrences can usually be successfully managed with surgery and radioiodine therapy, as are some isolated distant recurrences, such as bone metastases. If these treatments are not possible, other therapeutic options such as external beam radiation therapy or systemic treatments should be considered. Major advances in systemic treatments have led to improved progression-free survival in patients previously considered for palliative treatments; among these treatments, the most promising results have been achieved with tyrosine kinase inhibitors (TKI). This review attempts to give a comprehensive overview of the current treatment options suited for recurrences and the new treatments that are available in cases where salvage surgery is not possible or in cases resistant to radioiodine.