Thyroid cancer

Thyroid cancer occurs in thyroid cells, a butterfly-shaped gland located at the base of your neck just below the Adam’s apple. Your thyroid produces hormones that regulate your heart rate, blood pressure, body temperature, and weight.

Thyroid cancer may not show any symptoms at first. However, as it grows, it can cause pain and swelling in your neck.

There are several types of thyroid cancer. Some grow very slowly while others can be very aggressive. Most thyroid cancer cases can be cured with treatment.

Thyroid cancer rates seem to be rising. Some doctors think this is because the new technology allows them to find small thyroid cancers that may not have been found in the past.

 

The symptoms

Thyroid gland showing the larynx and trachea

Thyroid gland Open Pop-up dialog

Thyroid cancer typically does not cause any signs or symptoms in the early stages of the disease. As thyroid cancer grows, it can cause:

  • A lump (nodule) that can be felt in the skin on your neck
  • Changes in your voice, including increased hoarseness
  • Difficulty swallowing
  • Pain in your neck and throat
  • Swollen lymph nodes in your neck
  • When to see a doctor
  • Make an appointment with your doctor if you experience any signs or symptoms that worry you.

 

Reasons

It is not clear what causes thyroid cancer.

Thyroid cancer occurs when cells in your thyroid undergo genetic changes (mutations). Mutations allow cells to grow and multiply rapidly. Cells lose the ability to die just as normal cells do. Abnormal thyroid cells that accumulate form a tumor. Abnormal cells can invade nearby tissue and spread (metastasize) to other parts of the body.

 

Types of thyroid cancer

Thyroid cancer is divided into types according to the types of cells found in the tumor. Your type is determined when a tissue sample from your cancer is examined under a microscope. The type of thyroid cancer is taken into account in determining your treatment and prognosis.

Types of thyroid cancer include:

  • Papillary thyroid cancer. Papillary thyroid cancer, the most common form of thyroid cancer, is caused by follicular cells that produce and store thyroid hormones. Papillary thyroid cancer can occur at any age, but most often affects people between the ages of 30 and 50. Doctors sometimes refer to papillary thyroid cancer and follicular thyroid cancer as differentiated thyroid cancer.
  • Follicular thyroid cancer. Follicular thyroid cancer also arises from the follicular cells of the thyroid. It usually affects people over the age of 50. Hurthle cell cancer is a rare and potentially more aggressive type of follicular thyroid cancer.
  • Anaplastic thyroid cancer. Anaplastic thyroid cancer is a rare type of thyroid cancer that starts in follicular cells. It grows rapidly and is very difficult to treat. Anaplastic thyroid cancer typically occurs in adults aged 60 and over.
  • Medullary thyroid cancer. Medullary thyroid cancer begins in thyroid cells called C cells that produce the hormone calcitonin. High levels of calcitonin in the blood can indicate medullary thyroid cancer at a very early stage. Some genetic syndromes increase the risk of medullary thyroid cancer, but this genetic link is rare.
  • Other rare species. Other very rare types of cancer that start in the thyroid are thyroid lymphoma that starts in the cells of the immune system of the thyroid and thyroid sarcoma that starts in the connective tissue cells of the thyroid.

 

Risk factors

Factors that can increase the risk of thyroid cancer include:

  • The female gender. Thyroid cancer is more common in women than men.
  • Exposure to high levels of radiation. Radiation therapy treatments to the head and neck increase the risk of thyroid cancer.
  • Some inherited genetic syndromes. Genetic syndromes that increase the risk of thyroid cancer include familial medullary thyroid cancer, multiple endocrine neoplasia, Cowden syndrome, and familial adenomatous polyposis.
  • Complications
  • Returning thyroid cancer
  • Despite treatment, thyroid cancer can return even if you have had your thyroid removed. This can happen if microscopic cancer cells spread beyond the thyroid before being removed.

 

Thyroid cancer may recur if:

  • Lymph nodes in the neck
  • Small pieces of thyroid tissue left behind during surgery
  • Other parts of the body, such as the lungs and bones
  • Recurrent thyroid cancer can be treated. Your doctor may recommend periodic blood tests or thyroid scans to check for signs of thyroid cancer recurrence.
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Prevention

Doctors aren’t sure what causes most cases of thyroid cancer, so there is no way to prevent thyroid cancer in people with average disease risk.

Prevention for high risk people

Adults and children with an inherited gene mutation that increases the risk of medullary thyroid cancer may consider thyroid surgery (prophylactic thyroidectomy) to prevent cancer. Thyroid cancer