The thyroid gland produces chemicals that regulate how the body uses energy. Thyroid cancer develops in any of several tissues of the thyroid gland. It is relatively uncommon compared to other cancers. Death from thyroid cancer is unusual, especially in young people. Thyroid cancer is found twice as often in women.
What is going on in the body?
The thyroid gland continues to function normally even when the cancer has taken up part of the thyroid. The cancer may spread, or metastasize, to other parts of the body. Those parts may show damage from the cancer.
What are the causes and risks of the disease?
In most cases, the cause of thyroid cancer is unknown. Rarely, cases are thought to have resulted from prior radiation to the neck.
Occasionally, several members of a family develop unusual combinations of thyroid and other endocrine (gland cell) cancers. People from countries where the iodine content in the food supply is either low or high are also at somewhat increased risk for thyroid cancer.
What can be done to prevent the disease?
Nothing can be done to prevent thyroid cancer except to minimize exposure to radiation.
How is the disease diagnosed?
If a person has a lump growing in the front of the neck near the thyroid gland, a healthcare provider may suspect cancer. Special x-rays or nuclear medicine imaging can show that the lump might be malignant but cannot prove it. A biopsy is done to remove tissue from the lump for examination in the laboratory.
Recent research has shown that the development of thyroid cancer may be related to a genetic abnormality. Because of this, genetic testing may be done if person has other family members with thyroid or similar cancers.
Long Term Effects
What are the long-term effects of the disease?
Untreated thyroid cancer will cause death. A person who undergoes successful treatment will be able to live a normal life. The cure rate for this cancer is high compared to the more common cancers.
What are the risks to others?
Thyroid cancer poses no risks to others.
What are the treatments for the disease?
The treatment choices depend on the the extent of the cancer:
surgery. The malignant tissue must be removed. Often the whole thyroid gland will be removed. Tissue around the thyroid may also be removed.
internal radiation. In certain cases after surgery, a radioactive substance or isotope, such as iodine-131, may be given in a drink. Any remaining abnormal tissue will absorb the isotope. The isotope will then kill this tissue.
- other treatments such as chemotherapy and external radiation therapy for cancers that are difficult to cure with surgery.
What are the side effects of the treatments?
The side effects depend on the treatment given:
Persons who have surgery to remove the thyroid gland need to take thyroid hormones for the rest of their lives.
Radioactive isotopes cause weakness, nausea, and fatigue. These side effects do not last long. There are usually no long-term effects.
The side effects of chemotherapy vary with the medication used.
- External radiation therapy causes side effects that depend on the area of the neck that is treated. Effects may include skin irritations, dry mouth, difficulty swallowing, and loss of appetite.
What happens after treatment for the disease?
The person will need to be monitored for many years to make sure the cancer has not come back. The daily dose of thyroid hormones may need to be adjusted. Otherwise the person can expect to live a normal life.
How is the disease monitored?
CT scans, thyroid scans, and chest x-rays will be performed to determine if the cancer has come back. Thyroid function blood tests will be done to make sure the dose of thyroid hormone is correct.
Brower, S.T, Williams, W.L., Vassilopoulou-Sellin, R.&Lustig, R. (1996). Endocrine tumors in Cancer Management: A Multidisciplinary Approach. PRR: Huntington, NY. pp. 468-490.