Condition Overview
Medullary thyroid carcinoma (MTC) is a rare type of thyroid cancer that originates from the parafollicular C cells (also known as Chief Cells) of the thyroid gland, which produce the hormone calcitonin. MTC accounts for approximately 3-4% of all thyroid cancers. It can occur sporadically or as part of a genetic syndrome known as multiple endocrine neoplasia type 2 (MEN2). MTC is known for its propensity to metastasize early to regional lymph nodes and distant organs.
Patients with MTC may present with a thyroid nodule, and in some cases, they may have symptoms related to high levels of calcitonin, such as diarrhea or flushing. Due to its association with genetic syndromes, MTC can also present with symptoms related to other endocrine tumors, such as pheochromocytomas or hyperparathyroidism in patients with MEN2. These should be tested before any treatment is offered.
Diagnosis involves measuring serum calcitonin and carcinoembryonic antigen (CEA) levels, which are typically elevated in MTC. Genetic testing for RET proto-oncogene mutations is recommended for all patients diagnosed with MTC to identify those with hereditary forms of the disease. Imaging studies such as ultrasound, CT scan, MRI, and PET scan help assess the extent of the disease.
Treatment Options
- Total Thyroidectomy
- Description: Total thyroidectomy involves the complete removal of the thyroid gland. It is the primary treatment for MTC and is often accompanied by the removal of regional lymph nodes to address potential metastasis. In some rare cases, removal of only a lobe of the thyroid is adequate, but the risk of recurrence is likely higher. Scarless thyroid surgery can be considered, but is generally not recommended.
- Indications: Confirmed MTC, hereditary MTC, presence of regional lymph node metastasis.
- Central Neck Dissection (CND)
- Description: CND involves the removal of lymph nodes and other tissues in the central compartment of the neck. It is typically performed during the initial thyroidectomy to address lymph node metastasis and reduce the risk of recurrence. Experience is especially valuable in ensuring the lack of recurrence.
- Indications: MTC with central compartment lymph node involvement, high-risk patients, recurrent or persistent MTC.
- External Beam Radiation Therapy (EBRT)
- Description: EBRT involves targeting the thyroid region or metastatic sites with high-energy radiation to kill cancer cells. It is used in cases where surgery is not possible or for recurrent disease. Radioactive Iodine (RAI) is not effective with MTC.
- Indications: Unresectable tumors, palliative treatment for metastatic disease, recurrence not responsive to other treatments.
- Targeted Therapy
- Description: Targeted therapy involves the use of drugs that specifically target molecular pathways involved in cancer cell growth and survival. Kinase inhibitors such as vandetanib and cabozantinib are approved for treating advanced or metastatic MTC.
- Indications: Advanced or metastatic MTC, disease not amenable to surgery or radiation, part of a multimodal treatment approach.
- Chemotherapy
- Description: Chemotherapy uses drugs to kill cancer cells or slow their growth. It is less commonly used for MTC but may be considered in cases of widespread metastatic disease that are not responsive to other treatments.
- Indications: Advanced or refractory MTC, part of a multimodal treatment approach.
Management of MTC requires a multidisciplinary approach involving endocrinologists, surgeons, oncologists, geneticists, and radiologists. The choice of treatment depends on the extent of the disease, genetic considerations, patient preferences, and overall risk assessment. Regular monitoring and follow-up are essential to detect any recurrence or progression and to adjust the management plan as needed. Having an experienced team such as that at the Russell Center ensures that you will have access to the widest range of options for your medullary thyroid carcinoma.
