Advanced Medullary Thyroid Cancer: Symptoms And Treatment

Medullary thyroid cancer (MTC) is a rare type of thyroid tumor accounting 4 to 5 % of all thyroid malignancies. It affects people of all ages, adults as well as children. It is a neuroendocrine cancerous growth originating from parafollicular cells or C cells of the thyroid gland. It means the tumor develops in cells that function similar to cells of nervous as well as endocrine system. The C cells produce calcitonin, a hormone which regulates level of calcium in the body.

Due to its rarity, it is difficult to get detected in its early stage.

Medullary thyroid cancer nodule is often detected in its advanced stage where the cancer cells have already spread to the lymph nodes of neck and eventually to other distant organs such as liver, brain, lungs and bone. Advanced medullary thyroid cancer has poor prognosis and the treatment is often palliative.

Symptoms Of Advanced Medullary Thyroid Cancer

Medullary thyroid cancer if detected in the early stage has good prognosis. But unfortunately the symptoms such as thyroid nodule, hoarseness of voice, swallowing difficulty appear when the cancer has significantly advanced and infiltrated the neck tissue.

Below are given some of the common signs and symptoms of medullary thyroid cancer.

  • Thyroid nodule in neck area is the common symptom, but by the time it appears on the neck region the disease has already spread to the lymph nodes of neck area.
  • Constant hoarseness of voice is another important symptom. It occurs when the nerve that controls the vocal cord is compressed by thyroid growth. This nerve is near the thyroid gland.
  • Difficulty in swallowing occurs when the enlarged tumor compresses the food pipe (esophagus) which runs behind the thyroid gland.
  • Coughing and shortness of breath for a prolonged period of time.
  • Diarrhea for long duration can be a symptom of medullary thyroid cancer. Calcitonin is secreted in high amount in this condition. It is a type of prostaglandin which causes hyper-motility of the intestine and is responsible for uncontrolled prolonged diarrhea.
  • Patient may complain of pain in bones if the cancer cells have infiltrated the bones.
  • Advanced medullary thyroid cancer causes abnormal loss of weight.

Causes Of Medullary Thyroid Cancer

The cause of medullary thyroid cancer is not known. This cancer is not connected with radiation therapy given for curing other forms of neck cancer. There are two type of medullary thyroid cancer namely sporadic and familial or hereditary cancer. Usually 70 to 80 percent of patients have sporadic variety.

There is no known history of any other relative having this condition. Sporadic form occurs in people over the age of 20. Women are more likely to be affected with this disease as compared to men. 20 to 25% patients may have family history of medullary thyroid cancer. MTC in children is always inherited.

Treatment Options For Medullary Thyroid Cancer

  • The primary line of treatment for medullary thyroid cancer is complete removal of thyroid gland. If there is an involvement of lymph nodes, they are also removed at the time of surgery.
  • After the removal of thyroid gland, patient may need hormone supplementation therapy throughout his life.
  • Radiation therapy is used when the cancer cells have spread to other organs such as bones and brain. Radiation beam is focused on the thyroid to target and destroy the cancerous cells. It may also be necessary after surgical removal of thyroid to destroy the left over cancer cells.
  • Chemotherapy drugs are also used to target and destroy the cancer cells in some cases.

For all forms of medullary thyroid cancer the 5 year survival rate is 80 to 90 percent. The 10 year survival rate is 60 % but it may depend on the stage of cancer and the period when the disease is diagnosed. The prognosis is better if the disease is within the limits of thyroid. It has poor prognosis if the cancer cells have spread to bone, liver, lungs and brain.