Medullary thyroid cancer (MTC) comprises 3% to 4% of all thyroid cancers. These tumors usually present as a mass in the neck or thyroid, often associated with lymphadenopathy, or they may be diagnosed through screening family members. MTC can also be diagnosed by fine-needle aspiration biopsy. Cytology typically reveals hypercellular tumors with spindle-shaped cells and poor adhesion.
The overall survival of patients with MTC is 86% at 5 years and 65% at 10 years. Poor prognostic factors include advanced age, advanced stage, prior neck surgery, and associated multiple endocrine neoplasia (MEN) 2B.[2,3,4]
Cannabis use for medicinal purposes dates back at least 3,000 years.[1,2,3,4,5] It was introduced into Western medicine in the 1840s by W.B. O'Shaughnessy, a surgeon who learned of its medicinal properties while working in India for the British East Indies Company. Its use was promoted for reported analgesic, sedative, anti-inflammatory, antispasmodic, and anticonvulsant effects.
In 1937, the U.S. Treasury Department introduced the Marihuana Tax Act. This Act imposed a levy of one dollar an ounce...
Approximately 25% of reported cases of MTC are familial. Familial MTC syndromes include MEN 2A, which is the most common; MEN 2B; and familial non-MEN syndromes. (Refer to the PDQ summary on Genetics of Medullary Thyroid Cancer for more information.) Any patient with a familial variant should be screened for other associated endocrine tumors, particularly parathyroid hyperplasia and pheochromocytoma. MTC can secrete calcitonin and other peptide substances. Determining the level of calcitonin is useful for diagnostic purposes and for following the results of treatment.
Family members should be screened for calcitonin elevation and/or for the RET proto-oncogene mutation to identify other individuals at risk for developing familial MTC. All patients with MTC (whether familial or sporadic) should be tested for RET mutations, and if they are positive, family members should also be tested. Whereas modest elevation of calcitonin may lead to a false-positive diagnosis of medullary carcinoma, DNA testing for the RET mutation is the optimal approach. Family members who are gene carriers should undergo prophylactic thyroidectomy at an early age.[5,6]
Thyroidectomy: Patients with medullary thyroidcancer should be treated with a total thyroidectomy, unless there is evidence of distant metastasis. In patients with clinically palpable medullary carcinoma of the thyroid, the incidence of microscopically positive nodes is more than 75%; routine central and bilateral modified neck dissections have been recommended. When cancer is confined to the thyroid gland, the prognosis is excellent.
External radiation therapy: External radiation therapy has been used for palliation of locally recurrent tumors, without evidence that it provides any survival advantage. Radioactive iodine has no place in the treatment of patients with MTC.
Palliative chemotherapy: Palliative chemotherapy has been reported to produce occasional responses in patients with metastatic disease.[9,10,11,12] No single drug regimen can be considered standard. Some patients with distant metastases will experience prolonged survival and can be managed expectantly until they become symptomatic.
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with thyroid gland medullary carcinoma. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.