Thyroid Cancer

The thyroid is a gland in the front of the neck. It makes hormones that help control many body functions, including how the body uses energy (metabolism). Thyroid cancer is an abnormal growth of cancerous (malignant) cells in the thyroid gland. There are four main types of thyroid cancer:

• Papillary cancer. This is the least harmful type of thyroid cancer. It typically affects women of childbearing age.
• Follicular cancer. This type of cancer is the most likely to come back after treatment (recur) and spread to other parts of the body (metastasize).
• Medullary cancer. This can be passed from parent to child (inherited). A person who inherits the gene for this cancer is at high risk for developing the cancer.
• Anaplastic cancer. This type may spread quickly to the windpipe (trachea) and cause breathing problems. This type of cancer is most common among people age 65 and older.

What are the causes?

The exact cause of thyroid cancer is not known.

What increases the risk?

Risk factors for thyroid cancer include:

• Exposure to radiation of the head, neck, or chest in the past, especially during infancy or childhood (such as from radiation therapy for cancer).
• Having a thyroid that is larger than normal (enlarged). This may also be called a thyroid goiter.
• A family history of thyroid disease.
• Being female.

What are the signs or symptoms?

Symptoms of thyroid cancer may include:

• Enlarged thyroid gland. This may look like a large lump or swelling in the lower, front area of the neck.
• Hoarseness or a change in how your voice sounds.
• A cough.
• Coughing up blood.
• Difficulty swallowing.
• Shortness of breath.

How is this diagnosed?

This condition may be diagnosed based on:

• Your symptoms and medical history.
• Imaging tests of the neck area, such as:
  • Ultrasound.
  • CT scan.
  • MRI.
  • PET scan.
• Blood tests.
• Removal and testing of a thyroid tissue sample (biopsy). This will help determine the type of thyroid cancer.

Your cancer will be assessed (staged) to determine how severe it is and how much it has spread.

How is this treated?

Most thyroid cancers are treated with surgery to remove most or all of the thyroid gland (thyroidectomy). In some cases, the lymph nodes in the neck that are close to the thyroid may also be removed during surgery. Lymph nodes are part of the body's disease-fighting (immune) system, and they are usually the first place that cancer spreads to.

Treatment may also involve:

• Radioactive iodine treatment. This is a procedure that involves swallowing a substance (radioactive iodine, or radioiodine) that gets absorbed by the thyroid and destroys cancerous tissue. This may be given to:
  • Destroy remaining tissue that could not be removed surgically.
  • Treat thyroid cancer that has recurred or metastasized.
• Medicines that kill cancer cells in the body (chemotherapy).
• High-energy rays that kill cancer cells in the body (radiation therapy). You may have this if your cancer has spread to your bones.
• A procedure to kill cancer cells in the thyroid by injecting them with alcohol (alcohol ablation).
• Medicines that help your body's immune system fight the cancer cells (immunotherapy).
• Thyroid hormone therapy to:
  • Replace the hormone in the body that is normally made by the thyroid.
  • Reduce the activity of (suppress) a hormone that activates the thyroid (thyroid-stimulating hormone, TSH).

Follow these instructions at home:

• Take over-the-counter and prescription medicines only as told by your health care provider.
• Consider joining a support group for people who have thyroid cancer.
• Eat a healthy diet that includes fruits and vegetables, whole grains, lean protein, and low-fat or nonfat dairy products.
• Work with your health care provider to manage any side effects of treatment.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if:

• You have nausea or vomiting.
• You have diarrhea.
• You have a rash.
• You have a fever.
• You have problems with urinating, such as:
  • A burning sensation while urinating.
  • Needing to urinate more often than usual.
  • Pain or difficulty urinating.
  • Blood in your urine.
• You develop a new cough.
• You have symptoms of too much thyroid hormone (hyperthyroidism), such as:
  • Nervousness or anxiety.
  • Weight loss without trying.
  • Sweating.
  • Difficulty sleeping.
  • Hair loss.
  • Heart palpitations.
  • Frequent bowel movements.
• You have symptoms of too little thyroid hormone (hypothyroidism), such as:
  • Fatigue.
  • Puffiness in your face, hands, or feet.
  • Weight gain without trying.
  • Feeling cold.
  • Constipation.

Get help right away if:

• You have chest pain.
• You have shortness of breath.
• You suddenly feel too weak or dizzy to stand or walk.

Summary

• Thyroid cancer is an abnormal growth of cancerous (malignant) cells in the thyroid gland.
• The exact cause of thyroid cancer is unknown. A number of factors increase the risk, including past exposure to radiation.
• Diagnosis is based on imaging studies and a biopsy.
• Most thyroid cancers are treated with surgery to remove most or all of the thyroid gland (thyroidectomy), followed by other treatments such as radiation therapy, hormone therapy, or radioactive iodine treatment.