Last update:
26-Sep-2007

Thyroid cancer represents 90% of all malignant tumors of the endocrine system and 0.5% of all deaths from cancer in man. It is common, as in adults at autopsy a 4-36% rate of thyroid cancer has been observed, and in clinical practice a 6-10% rate in nodules. Based on the frequency of nodules in clinical practice, it is estimated that 3.5% of Greek adults (aged older than 18 years) have thyroid cancer and based on autopsy findings 10%. It occurs more frequently in women than in men with a ratio of 2-3/1. The main types of thyroid cancer are papillary and follicular (differentiated), medullary and anaplastic, with frequencies of 70-80%, 15-20%, 5-8%, and 3-5%, respectively. The main causes are genetic mutation, irradiation of the head and neck and iodine deficiency. Diagnosis is based on the history, clinical examination, laboratory and imaging evaluation and mainly on fine-needle aspiration cytology. Treatment for differentiated and medullary carcinomas is total or near total thyroidectomy with excision of infiltrated neck lymph nodes, if any. In differentiated thyroid carcinomas radioactive iodine-131 is administered postsurgically for the destruction of any remnant tissue, while radiotherapy and chemotherapy, as given in medullary carcinomas which do not take up radioactive iodine, has very poor results. In anaplastic carcinomas an effort is made to remove the main part of the tumor for the alleviation of obstructive phenomena, but radiotherapy and chemotherapy have poor results, as the tumors grow very quickly. In all cases thyroxine is administered. The prognosis, except for anaplastic carcinomas, is better than in other types of cancer. The 10-year survival rate in papillary carcinoma is 93%, in follicular 85% and in medullary carcinoma 75%, but in anaplastic carcinoma it is 2-6 months, very rarely extending beyond 1 year. Due to the good prognosis of most cases of thyroid cancer, and despite its high frequency, screening of the general population is not indicated.

Key words: Differentiated thyroid carcinoma, Human recombinant TSH, Multiple endocrine neoplasia, Thyroglobulin.