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The
th Annual Meeting of March 10-11, 2018 The Endocrine Society and The Diabetes Association of the R.O.C. (Taiwan)
PL-1
TARGET THERAPIES IN ADVANCED THYROID CANCER ROSSELLA ELISEI Associate Professor of Endocrinology, University of Pisa
Thyrosine kinase inhibitors (TKI) are nowadays the new drugs involved in the therapy of advanced and progressive thyroid cancer (MTC). Four of them, have been approved by both FDA and EMA for this purpose: lenvatinib and sorafenib for dedifferentiated thyroid cancer (papillary and follicular [PTC and FTC]) and vandetanib and cabozantinib for medullary thyroid cancer (MTC). As well known, TKI are cytostatic drugs that are able to block the activities of several tyrosine kinases including BRAF and RET which are the major players in the pathogenesis of both PTC/FTC and MTC. For this reason TKI must be used when there is an evident progression of the metastatic disease with the intent to block this progression. A significant increase of the serum markers, such as thyroglobulin and calcitonin, can suggest that the disease is in progression but only after a documented radiological progression according to RECIST, the TKI will be prescribed. However, all the phase III clinical trials, SELECT (for lenvatinib), DECISION (for Sorafenib), ZETA (for vandetanib) and EXAM (for cabozantinib), showed that these drugs are also able to determine a shrinkage of the lesions with a relevant objective response rate (ORR). On the basis of this objective results they can be also used with the purpose to reduce the size of lesions whose location can be dangerous for the life of our patients such as vertebral lesions that, if growing more, can rapidly compress the spinal cord determing para- or tetraplegia. Moreover, anytime there is a single lesion that is progressing or representing a clinical problem for our patient, the possibility of a local treatment, such as external radiotherapy, laser ablation, chemoembolization ecc, should be considered. Finally, anytime we decide to prescribe a TKI, the possible side effects of the drug, that are very similar among all TKI but with some peculiarities for each drug, must be considered. A very accurate, and possibly multidisciplinary, evaluation of the general health conditions and the other co-morbidities of the patient must be done before starting the systemic TKI therapy.
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