Metastatic thyroid cancer is cancer starting in the thyroid gland in the neck that has spread beyond the thyroid gland to the lymph nodes of the neck and other distant organs. The National Cancer Institute (NCI) notes that the commonest sites of thyroid cancer metastasis are the bones and lungs.Treatment of metastatic thyroid cancer depends on the type of cancer, the extent of spread and the patient's health status. There are several treatment options available.
Surgery
For all types of thyroid cancer, total thyroidectomy--the removal of the thyroid gland in its entirety--is suggested. Removal of the lymph nodes in the neck by radical neck dissection, is also recommended by the American Cancer Society (ACS) to reduce the chances of further spread. Resection of isolated metastasis is sometimes possible. In some cases of metastatic thyroid cancer where surgical removal is not possible, palliative surgery to relieve discomfort can be done. One example of palliative surgery in metastatic thyroid cancer, according to the ACS, is a tracheostomy--an opening in the trachea below the level of the thyroid gland to allow air into the lungs and to bypass a blockage of the airway resulting from the cancer.
Radioactive Iodine Therapy
The thyroid cells take up iodine from the blood to produce thyroid hormones. Iodine labeled with radioactivity, called radioactive iodine (RAI), or I-131, when taken up by the thyroid gland or thyroid cancer cells, leads to their destruction. According to the ACS, RAI is used to destroy any thyroid tissue left behind from surgery or any metastasis from thyroid cancer anywhere else in the body. Thyrotropin, or thyroid stimulating hormone (TSH) is sometimes given to increase the uptake of TAI and the effectiveness of the treatment.
External Beam Radiation therapy
The use of high powered radiation to destroy cancer cells is also employed in metastatic thyroid cancer. The form of radiation applied in metastatic thyroid cancer is external beam radiation therapy (EBRT). It is used after surgery to take care of any leftover cancers in the neck. Radiation therapy is also used to control pain from metastatic thyroid cancer in advanced stages. According to the ACS, EBRT is reserved for thyroid cancers that do not take up radioactive iodine, like medullary and anaplastic thyroid cancers.
Hormonal Therapy
Thyroxine, the thyroid hormone, is given to patients with metastatic thyroid cancer according to the NCI. The hormone suppresses TSH production, which encourages the growth of thyroid cancer. This therapy is reserved for patients with thyroid cancer types that do not respond to TAI. According to the American Society of Clinical Oncology (ASCO), thyroid hormone is also given as hormone replacement therapy after the thyroid gland is removed by surgery.
Chemotherapy
Chemotherapy is the use of drugs to destroy cancer cells. According to the ACS, it can be combined with external beam radiation therapy in the treatment of advanced or metastatic thyroid cancer, especially those cancers, which do not respond to RAI. Some of the drugs used in metastatic thyroid cancer are doxorubicin and cisplatin.
Other Treatments
The NCI suggests participation in clinical trials of newer treatments for metastatic thyroid cancer. Clinical trials may include the use of targeted therapy in thyroid cancer, or different combinations of chemotherapy drugs. Other supportive treatments like morphine or other analgesics for pains, multivitamins and food supplements are also used to improve quality of life and treat adverse reactions to other modes of treatment.
References
- National Cancer Institute: Thyroid Cancer Treatment
- American Cancer Society: Treatment of Thyroid Cancer by Stage
- American Cancer Society: Thyroid Cancer: External Beam Radiation Therapy
- American Society of Clinical Oncology: Thyroid Cancer Treatment
- American Cancer Society: Thyroid Cancer: Chemotherapy
