Thyroid Cancer Basics and Information

Close-up of a female doctor doing a medical examination. The focus is on the mature adult woman being examined.
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Thyroid cancer is one of the more uncommon cancers in the United States, accounting for less than 2% of all new cancers in the United States annually.

Although thyroid cancer is still a cancer that requires treatment and lifelong monitoring, and can have debilitating effects on patients, survival rates are quite high, with 95% of all thyroid cancer patients achieving what would be considered a cure, or long-term survival without a recurrence of the cancer.

 

Thyroid cancer affects women two to three times more than men. Besides what appears to be a hormonal or gender connection, and risks of exposure to radioactive materials, the causes of thyroid cancer are, for the most part, not known.

There are four types of thyroid cancer:

  • Papillary
  • Follicular
  • Medullary
  • Anaplastic

Papillary cancer is the most common type of cancer, perhaps because papillaries are quite common in the thyroid gland. Papillary cancer mostly involves one side of the thyroid and sometimes spreads into the lymph nodes. The cure rate is very high.

Follicular cancer, the second most common type of thyroid cancer, is somewhat more malignant than papillary. The thyroid gland is comprised of follicles which produce thyroid hormones. With follicular thyroid cancer, the cancer doesn't usually spread to the lymph nodes, but instead can spread to arteries and veins of thyroid gland and more distantly (lung, bone, skin, etc).

The spread of follicular cancer -- metastasis -- is still uncommon however. Follicular cancer is more common in older people. Again, the long -term survival rate is high.

Medullary thyroid cancer is the third most common type of thyroid cancer. This type of thyroid cancer originates in the upper central lobe of the thyroid.

It spreads to the lymph nodes much earlier than papillary or follicular cancers. Medullary thyroid cancer differs from papillary and follicular cancer in that it does not arise from cells that produce thyroid hormone, but instead from C cells. These C cells make the hormone calcitonin. This type of cancer can run in families, and also has a good cure rate.

Anaplastic is the rarest and most serious thyroid cancer. It can spread early to lymph nodes, thus usually the cause for a visit to the doctor is a mass in the neck. It also is the form of thyroid cancer most likely to spread to other organs beyond the thyroid or lymph nodes. This type of thyroid cancer is more common in those over 65 and in men. Long-term survival rates are far less than for the other three types of cancer.

Treatment for thyroid cancer depends on the type of cancer, the size, and staging, among other factors. In most cases of thyroid cancer, the thyroid gland is surgically removed, known as a thyroidectomy. Depending on the type of cancer and its prognosis, radioactive iodine (RAI) treatment, also known as remnant ablation, is given to kill off any thyroid tissue remaining after the thyroid surgery.

Some less common but advanced types of thyroid cancer may involve external beam radiation treatment, or other types of anti-cancer medications. After surgical removal of the gland, thyroid cancer patients require lifelong thyroid hormone replacement medication. For some types of thyroid cancer, experts recommend that that medication be at a dose that is "suppressive," meaning that the amount of medication keeps the TSH level low or undetectable, to help prevent a recurrence of the cancer.  

Monitoring will take place to watch for any possible recurrence of the cancer. This may include blood tests, visual tests such as ultrasound, PET scan, MRI or CT scans, radioactive uptake scans of the thyroid gland. The frequency and type of monitoring performed depends on the type of thyroid cancer that is diagnosed and the potential aggressiveness or risk of a recurrence. 

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