Treatments for differentiated thyroid cancer
The following are treatment options for papillary or follicular carcinoma, which are grouped together as differentiated thyroid cancer. Your healthcare team will suggest treatments based on your needs, the stage of the cancer and the risk group. They will work with you to develop a treatment plan.
Surgery is the first treatment for differentiated thyroid cancer. The type of surgery done depends on your age, the size of the tumour and if the cancer has spread outside the thyroid.
Lobectomy removes one side, or lobe, of the thyroid. It may be done for some low-risk cancers. If the tumour is 1 cm or smaller and only in one side of the thyroid, a lobectomy is usually the only treatment needed. A lobectomy may also be done if the tumour is 1–4 cm in size and only in the thyroid.
Total thyroidectomy completely removes the thyroid. It is the most common type of surgery done for differentiated thyroid cancer. It can be done for cancers in any risk group. It is done if the doctor plans to use radioactive iodine therapy (also called RAI therapy).
Neck dissection removes lymph nodes from the neck. The surgeon may also remove other tissues around the thyroid. It is done at the same time as a total thyroidectomy. Neck dissection is usually done for intermediate-risk and high-risk differentiated thyroid cancers. It is done if a biopsy shows there is cancer in the lymph nodes in the neck or the doctor thinks there is cancer in these lymph nodes based on the results of imaging tests such as ultrasound or CT scan. The type of neck dissection done depends on which lymph nodes in the neck the doctors think have cancer in them and how the lymph nodes look during surgery. It also depends on which tissues outside of the thyroid the cancer has spread to.
Surgery for metastasis could be used to treat high-risk differentiated thyroid cancer that has spread to other organs and is causing symptoms. Find out more about metastatic cancer.
Hormonal therapy is a standard treatment after surgery for differentiated thyroid cancer. 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 may be offered after surgery for intermediate- or high-risk differentiated thyroid cancer. It is used to kill any cancer cells and normal thyroid tissue that remain after surgery, and treat cancer that has spread to lymph nodes or other parts of the body. Radioactive iodine therapy or external beam radiation therapy are used.
Radioactive iodine therapy uses a type of radioactive iodine called iodine-131, or I-131. It may be offered if the:
- tumour is larger than 4 cm
- tumour has grown through the thyroid and spread to nearby tissues and structures
- cancer has spread to lymph nodes in the neck
- cancer is an aggressive variant or has other high-risk features when seen under a microscope
- cancer comes back in the same place or close to where it started (called a local or regional recurrence)
- cancer has spread to other parts of the body (called distant metastasis)
External beam radiation therapy is mainly used when radioactive iodine therapy will not work because the cancer cells do not absorb, or take up, iodine. It is also used as a palliative treatment when the cancer can’t be removed with surgery (it is unresectable) or metastatic cancer causes symptoms. Sometimes external beam radiation therapy is used when the cancer has spread to a lot of lymph nodes. It may also be used if doctors find a very small amount of cancer in the tissue removed along with the tumour or the thyroid (called microscopically positive surgical margins).
You may be offered targeted therapy for locally advanced or metastatic differentiated thyroid cancer. It may also be given if the cancer doesn’t respond to other treatments. It is typically used when radioactive iodine therapy has not worked or has stopped working. The targeted therapy drugs used for differentiated thyroid cancer are sorafenib (Nexavar) and lenvatinib (Lenvima). They are given as a pill.
You may be asked if you want to join a clinical trial for differentiated thyroid cancer. Find out more about clinical trials.
Taking action against all cancers
The latest Canadian Cancer Statistics report found that of all newly diagnosed cancers in 2017, half are expected to be lung, colorectal, breast and prostate cancers. Learn what you can do to reduce the burden of cancer.