What is Medullary Thyroid Cancer?
Medullary thyroid cancer (MTC) is the third most common type of cancer that affects the thyroid, a small gland located in the front part of your neck, that creates some crucial hormones: triiodothyronine (T3) and thyroxine (T4); which are responsible for maintaining the body metabolism regulation. MTC can spread to other organs through the lymph nodes in the early stages of the disease, which makes it more aggressive than papillary and follicular thyroid cancer.
Medullary Thyroid Cancer Signs and Symptoms
MTC doesn’t cause any sign or symptom in the early stages of the disease. Basically, because its middle location. However, when the nodule is big enough, there might be some symptoms associated:
- A lump sensation in the front part of your neck.
- Difficulty to swallow or breath.
- Mild pain in your neck.
- Hoarseness and voice changes.
- Swollen lymph nodes around the thyroid.
Additionally, MTC produces many substances, including calcitonin, prostaglandins, serotonin, among others. Usually, people with advanced MTC suffer from diarrhea, which is caused by the abnormally high additional substances.
Medullary Thyroid Cancer Causes
MTC develops in the middle part of the gland, a portion called “medulla”, which contains a special type of cells called parafollicular C cells, responsible for the production of some hormones. MTC occurs after some genetic alterations -mutations- in these cells.
MTC can develop either as a sporadic disease or as an inherited disorder, associated with others endocrine neoplasia, a condition known as multiple endocrine neoplasias (MEN). There are some differentiating characteristics for each group:
Sporadic Medullary Thyroid Cancer
- Is the most common type.
- Affects more women than men and people around 40-50 years old.
- Prognosis gets worse over 55 years.
Hereditary Medullary Thyroid Cancer
- Affects equally women and men.
- Is associated with MEN condition.
- Strongly related with medullary thyroid cancer family history and RET gene mutation.
Medullary Thyroid Cancer Diagnosis
Unfortunately, most people affected by MTC receive a diagnosis in advanced stages of the disease, due to the absence of symptoms and the internal slow growth of the nodule. However, in case you or your doctor detect a lump in your neck, some additional tests to confirm its nature will be done, including:
- Thyroid ultrasonography. This technique provides good quality information about the shape of the nodule and helps doctors determining its malignant characteristics.
- Fine-needle aspiration (FNA) biopsy. During the procedure, your doctor will insert a very fine needle into the suspicious nodule and will remove a sample of cells for microscopic analysis to look after cancer cells.
- Blood test. In order to detect the levels of some hormones like calcitonin.
Medullary Thyroid Cancer Treatment
Similar to papillary and follicular thyroid cancer, MTC treatment also involves surgery. However, since this type of cancer frequently spread to the lymph nodes of the neck, curation rates are lower.
Your doctor will suggest the removal of the thyroid -thyroidectomy-, could be unilateral (hemi thyroidectomy) or bilateral (total thyroidectomy) in order to remove the malignant nodule and eliminate any possibility for additional cancerous nodule formation. Also, your doctor will remove any lymph node around your neck that looks suspicious
In case you have a high risk for developing MTC, like a detected RET gene mutation, your doctor will suggest a prophylactic thyroidectomy to prevent cancer in the future.
Thyroid Hormone Supplementation Therapy
As a way to provide your body with the important thyroid hormones that you won’t any longer produce after total thyroidectomy, you will need to take a daily and life-long supplementary thyroid hormone treatment, a medication called levothyroxine.
Contrary to papillary and follicular thyroid cancer, medullary thyroid cancer doesn’t respond to radioactive iodine ablation or thyroid suppressive therapy. However, radiation therapy and chemotherapy can be helpful after surgery.
Long-Term Follow Up
After treatment, your doctor will monitor the levels of a tumor marker called carcinoembryonic antigen (CEA) and the hormones produced by C cells to keep track of how well the treatment is working or if cancer has come back.