Abstract: Normally, thyroid cancer is a disease with a good prognosis, but about 30% of the tumors dedifferentiate and may finally develop into highly malignant thyroid carcinoma with a mean survival time of less than 8 months. Due to the loss of thyroid-specific functions associated with dedifferentiation. These tumors are inaccessible to standard therapeutic procedures such as radioiodine therapy and thyroxine-mediated thyrotropin suppression. Medullary thyroid carcinomas are also highly aggressive. Here, therapy is limited to surgery, and no alternative is left if patients do not respond to this standard procedures. Several novel approaches are currently being tested for the treatment of thyroid cancer. Many of them utilize methods of gene therapy:① reintroduction of the tumor suppressor p53; ② suicide gene therapy; ③ anti-tumor immune response by expression of an adenovirus-delivered interleukin-2(IL-2)gene; ④ immune response by DNA vaccination against the tumor marker calcitonin; ⑤ transduction of the thyroid sodium/iodine transporter gene to make tissues that do not accumulate iodide treatable by radioiodide therapy; ⑥ blocking of the expression of the oncogene c-myc by antisense oligonuleotides; ⑦ radioimmunotherapy by a radiolabelled antibody; ⑧ retinoic acid is used for a redifferentiation therapy, and ⑨ somatostatin.