Thyroid cancer

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Treatments for poorly differentiated carcinoma

The following are treatment options for poorly differentiated thyroid carcinoma. Your healthcare team will suggest treatments based on your needs and work with you to develop a treatment plan.


Surgery is the first treatment for poorly differentiated carcinoma. The type of surgery done depends on the location of the cancer.

Total thyroidectomy completely removes the thyroid. It is the standard surgery done for all poorly differentiated carcinomas.

Neck dissection removes lymph nodes from the neck. The surgeon may also remove other tissues around the thyroid. Neck dissection is done if any lymph nodes in the neck are enlarged or if it is likely that cancer has spread to these lymph nodes. It is done at the same time as a total thyroidectomy. The type of neck dissection done depends on which lymph nodes in the neck the doctors think have cancer in them based on the results of imaging tests, such as ultrasound or CT scan, and how the lymph nodes look during surgery. It also depends on which tissues cancer has spread to outside of the thyroid.

Palliative surgery may be done if a large tumour causes symptoms or it blocks an airway or the esophagus. The surgeon will remove all of the tumour or as much of the tumour as possible (called debulking).

Hormonal therapy

Hormonal therapy is a standard treatment after surgery for poorly differentiated carcinoma. It is used to replace the hormone thyroxine, which would normally be made by the thyroid. It is also used to slow down the growth of any remaining cancer cells and help prevent the cancer from coming back, or recurring.

The type of hormonal therapy used is levothyroxine (Synthroid, Eltroxin). It is given as a pill once a day. Levothyroxine may not be started until radioactive iodine therapy is finished. You will have to take levothyroxine for the rest of your life if you have a total thyroidectomy.

Radiation therapy

Radiation therapy is usually offered after surgery for poorly differentiated carcinoma. It is used to kill any cancer cells and normal thyroid tissue that remain after surgery, treat cancer that has spread to lymph nodes or other parts of the body and control the growth of the cancer.

Radioactive iodine therapy (also called RAI therapy) is the most common type of radiation therapy used. It uses a type of radioactive iodine called iodine-131, or I-131. External beam radiation therapy may be used if the surgeon couldn’t completely remove all of the cancer. It may be used alone or in addition to radioactive iodine therapy.

If you can’t have or don’t want cancer treatment

You may want to consider a type of care to make you feel better rather than treat the cancer itself. This may be because the cancer treatments don’t work anymore, they’re not likely to improve your condition or they may cause side effects that are hard to cope with. There may also be other reasons why you can’t have or don’t want cancer treatment.

Talk to your healthcare team. They can help you choose care and treatment for advanced cancer.

Clinical trials

You may be asked if you want to join a clinical trial for poorly differentiated carcinoma. Find out more about clinical trials.