Treatment of familial medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy, which is familial in 25-29% of cases. Familial MTC is due to germ-line mutations in the RET proto-oncogene. It can occur either alone or as the thyroid manifestation of MEN 2 syndromes; the disease is inherited in an autosomal dominant fashion with age-related penetrance. The treatment of choice is surgery. Early diagnosis and an adeguate initial operation provide the best chance of cure. Hence, the diagnosis should be made preoperatively. Genetic testing can identify almost all affected individuals with hereditary disease and permits prophylactic/early thyroidectomy in gene carriers. Total thyroidectomy and lymphadenectomy of the cervicocentral compartment is mandatory in all patients. In addition, bilateral dissection of the cervicolateral compartment should be done in all cases with more than microscopic disease. Plasma calcitonin is an excellent marker for postoperative follow-up. Treatment of persistent/recurrent disease is primarily surgical. Hence, a reoperative cervical lymphadenectomy should be considered in patients with persistently elevated calcitonin levels and no signs of distant metastases. Chemotherapy and external radiotherapy have little impact on the course of avanced disease; more promising is metabolic radiotherapy with Y90-DOTATOC in patients with somatostatin receptor-positive tumours.