Systemic treatment of advanced differentiated and medullary thyroid cancer. Overview and practical aspects.

In the last few years, three new drugs for targeted systemic therapies have been approved for advanced and progressive thyroid cancer, namely vandetanib and cabozantinib for medullary and sorafenib for radioiodine refractory differentiated thyroid cancer. Patient selection by an interdisciplinary team and education of patients by the treating physicians play a major role when such a treatment is considered and initiated. Only patients with significant tumor burden and/or symptomatic disease or progression, which cannot be controlled by local therapies, should be treated. In order to preserve quality of life, the management of adverse effects is of utmost importance. Due to the mechanism of action of these tyrosine kinase inhibitors, the reliability of serum tumour markers, calcitonin and thyroglobulin, is limited for the assessment of response and follow-up, therefore morphological and metabolic imaging is of great importance. Minor or localized progression should not automatically trigger the termination of treatment or change of drug. In the near future, it is expected that additional drugs become available.