Thyroid Cancer

Thyroid cancer generally doesn’t cause symptoms. In the rare cases where symptoms arise, they include:

• Most often, a lump in your neck
• Pain in your neck that may shoot up into the jaw and ears
• Difficulty breathing or swallowing
• A persistent cough or tickling in the throat
• Changes to your voice, including hoarseness

The above symptoms can be caused by other conditions and do not necessarily mean you have thyroid cancer. However, if you are experiencing symptoms, see your doctor so that the problem can be diagnosed and treated.

Thyroid cancer is cancer that occurs in the cells of the thyroid gland. The thyroid gland is shaped like a butterfly and is located under the Adam’s apple in front of the neck. Most cases of thyroid cancer can be cured.

The thyroid gland, which is made up of a right lobe and a left lobe, produces and secretes thyroid hormones into the bloodstream. Thyroid hormones play an important role in controlling such functions as body temperature, heart rate, blood pressure and weight.  An overactive thyroid can lead to hyperactivity, the "jitters," and an irregular heart rhythm, while an underactive thyroid will often cause fatigue and sluggishness.

How does thyroid cancer occur?

Sometimes abnormal cells in the thyroid gland begin to grow uncontrollably, causing one or more nodules to form. The reason why this happens is unknown but according to Cancer Research UK , definite risk factors include radiation, a family history of thyroid cancer, being overweight and diabetes. Cancerous nodules can invade the tissues of the neck, spread to the surrounding lymph nodes, or to the bloodstream, and then to other parts of the body.

What types of thyroid cancer are there?

There are 4 types of thyroid cancer. These are:

• Papillary thyroid cancer: This is the most common type, estimated by Cleveland Clinic to make up over 70% of all thyroid cancers. This cancer has a generally excellent outlook, as it is usually not fast growing and does not spread quickly into surrounding tissue.
• Follicular thyroid cancer: This type makes up 10% - 15% of thyroid cancers. Follicular cancer can travel through the bloodstream and into other areas of the body, such as the lungs or bone.
• Medullary thyroid cancer: This type accounts for around 5% of all thyroid cancers. This type is more likely to run in families and be associated with other endocrine problems.
• Anaplastic thyroid cancer: This type is rare and found in less than 2% of people diagnosed with thyroid cancers. It is the most aggressive and advanced thyroid cancer, and also the least likely to respond to treatment. 

To diagnose thyroid cancer, one or more of the following procedures may be used:

• Physical exam: Your doctor may conduct a physical exam to check for lumps and enlarged lymph nodes.
• Blood tests: Blood tests check for levels of thyroid-stimulating hormones in your body body. An elevated level of one hormone in particular, calcitonin, is a sign of thyroid cancer.
• Thyroid scan: With this scan, a special camera and radioactive iodine (either injected or given as a pill), produce an image of the thyroid on a computer screen. However, this test is not ordered frequently.
• Imaging tests: Imaging tests use various methods to determine location, size and spread of thyroid cancer. Methods include x-rays, injection of dyes or radioactive substances in a vein, radio waves, and a magnet.
• Fine-needle aspiration (FNA) biopsy: If your doctor finds a thyroid nodule in your neck, he or she can determine if it is cancerous by doing an FNA. During this procedure, a thin needle is inserted through the skin and into the thyroid gland and/or nodules. A sample of cells is removed and examined for cancer.

After thyroid cancer is found, your doctors will discuss your treatment options with you. Your thyroid cancer treatment options depend on the type of your thyroid cancer, your overall health and your preferences. Your treatment plan may include:

• Surgery: The main treatment for all forms of thyroid cancer is surgery. According to the American Thyroid Association , the generally accepted approach is to remove the entire thyroid gland in what is called a total thyroidectomy. Thyroid surgery carries the risk of damage to your parathyroid glands and to the nerves connected to your vocal cords.
• Thyroid hormone therapy: After surgery, you will need to take thyroid hormone medication for the rest of your life. This medication helps by supplying the missing hormone your thyroid will normally produce. It also suppresses a hormone from the pituitary gland that can speed the growth of any remaining cancer cells.
• Radioactive iodine treatment: Thyroid cells and most thyroid cancers absorb and concentrate iodine very readily. For this reason, radioactive iodine can be used effectively to destroy all remaining normal and cancerous thyroid tissue after surgery. This is often used to treat thyroid cancer that recurs after treatment or that spreads to other areas of the body.
• External beam radiation therapy: In this treatment, high-energy beams of radiation are directed at the cancer to kill cancer cells. External beam radiation therapy is generally used to treat thyroid cancer that has spread to the bones.
• Chemotherapy: Chemotherapy is a drug treatment that uses chemicals to kill cancer cells. These can be taken orally or injected into a vein. Chemotherapy is not commonly used in the treatment of thyroid cancer, but it may benefit some people who have not responded to other therapies.

In many cases, it is not possible to prevent thyroid cancer. Doctors aren't sure what causes most cases of thyroid cancer, so there's no known way to fight against thyroid cancer in those who have an average risk of the disease. In some cases, however, there are some measures that can be taken:

• Having preventative (prophylactic) surgery: Changes in specific genes can occur in members of the same family. These gene changes are associated with an increased risk of thyroid cancer. A person might choose having his/her currently cancer-free thyroid totally removed to prevent cancer from developing there. Those who test positive but have no symptoms of thyroid cancer may decide to have their thyroid removed to prevent the disease.
• Taking potassium iodide tablets: If you have been exposed to large amounts of radiation, speak to your doctor about taking potassium iodide tablets, which can protect the thyroid gland from the effects of radiation.