Safety and Efficacy of Sorafenib in Patients With Advanced Thyroid Cancer: a Phase II Clinical Study

* Older than 18 years. * Confirmed histological diagnosis of differentiated thyroid cancer, whether metastatic or unresectable, for whom conventional curative or palliative therapeutic options do not exist or are not effective. It includes patients with lesions visible in images, that have no uptake at therapeutic doses of iodine, or patients with iodine avid lesions, that keep progressing after therapeutic doses (greater than 100 mCi). Also comprises patients with persistent local disease progression not amenable to surgical management or radiation therapy management. * The time that has passed since the last treatment until inclusion must of at least six (6) months. * There must be at least 1 lesion that can be adequately measured according to the RECIST (v.1.1) criteria \[See Appendix 1\]. * Neck or lung lesions, surgery declared unresectable. * Patients must have a ECOG score less than 2 and life expectancy greater than 3 months. * Adequate bone marrow, liver and renal functions defined by the following laboratory parameters, taken no more than 7 days after consent signing: white blood cell count, \> 3,000/uL; absolute neutrophil count, \> 1,500/mm3; platelets, \> 100,000/mm3; hemoglobin, 9 g/dl; serum creatinine, \< 1.5 times the upper limit of normal (ULN) or creatinine clearance in urine for 24 hours \> 75 cc/min; total serum bilirubin, \< 1.5 times the ULN; glutamic oxaloacetic transaminase (SGOT), \< 1.5 times the ULN; serium alkaline phosphatase, \< 1.5 times the ULN; prothrombin time (PT-INR) and partial thromboplastin time (PTT), \< 1.5 times the ULN. * The patient must be physically, intellectually, and emotionally able to take the oral medicine. * Patient must not be a candidate for surgery or radiotherapy with curative intent * Women of childbearing potential should have a negative serum pregnancy test performed within 7 days prior to start of treatment. Post-menopausal women (at least one year with no menstruation) and surgically sterilized women do not require pregnancy tests. * Women and also men of childbearing potential should agree to use adequate contraceptive methods * Significant medical conditions including an uncontrolled hypertension (systolic blood blood pressure \>150 mmHg or diastolic blood pressure \> 90mmHg) * Significant Hemorrhage or bleeding events, CTCAE grade 3 or higher, within 12 weeks of randomization. arterial or venous thrombotic or embolic events within the past 6 months (including cerebrovascular accidents and transient ischemic attacks, deep vein thrombosis, pulmonary embolism and arterial thrombosis). * Recent major surgery or open biopsy procedure (within 4 weeks of study entry) * Bone lesions will be excluded, by its susceptibility to radiotherapy and bisphosphonates management. * Wounds, ulcers or bone fractures that are non healing * Pregnancy or lactation. * A personal history of a second neoplasm with the exception of squamous-cell or basal-cell skin cancer that is suitably treated, in situ cervical cancer, or any other previously treated cancer when one has stayed free of disease for 5 years or more. * Prior use (4 weeks before admittance to the study) of chemotherapy or cancer immunotherapy. * Prior use of of tyrosine kinase inhibitors or other targets agents, or monoclonal antibodies that target VEGF or VEGF receptors. * Known or suspected allergy or hypersensitivity to sorafenib * Having received radiotherapy in the 4 weeks preceding admittance to the study. * Any condition according to the judgment of the treating physician that could jeopardize the patient's safety or compliance to the study. * All patients that are admitted to the study must voluntarily consent to their participation and the same must be recorded in a written informed consent form.