Treatment of Thyroid Cancer, by Type and Stage

The type of treatment your doctor will recommend depends on the type and stage of the cancer and on your overall health. Talk to your doctor if you have any questions about the treatment plan they recommend.

Papillary cancer and its variants

Most cancers are treated with removal of the thyroid gland (thyroidectomy), although small tumors that have not spread outside the thyroid gland may be treated by just removing the side of the thyroid containing the tumor (lobectomy). If lymph nodes are enlarged or show signs of cancer spread, they will be removed as well.

In addition, recent studies have suggested that people with micro-papillary cancers (very small thyroid cancers) may safely choose to be watched closely with routine ultrasounds rather than have immediate surgery.

Even if the lymph nodes aren’t enlarged, some doctors recommend central compartment neck dissection (surgical removal of lymph nodes next to the thyroid) along with removal of the thyroid. Although this operation has not been shown to improve cancer survival, it might lower the risk of cancer coming back in the neck area. Because removing the lymph nodes allows them to be checked for cancer, this surgery also makes it easier to accurately stage the cancer. If cancer has spread to other neck lymph nodes, a modified radical neck dissection (a more extensive removal of lymph nodes from the neck) is often done.

Treatment after surgery depends on the stage of the cancer:

• Radioactive iodine (RAI) treatment is sometimes used after thyroidectomy for early stage cancers (T1 or T2), but the cure rate with surgery alone is excellent. If the cancer does come back, radioiodine treatment can still be given.
• RAI therapy is often given for more advanced cancers such as T3 or T4 tumors, or cancers that have spread to lymph nodes or distant areas. The goal is to destroy any remaining thyroid tissue and to try to treat any cancer remaining in the body. Areas of distant spread that do not respond to RAI might need to be treated with external beam radiation therapy, targeted therapy, or chemotherapy.

People who have had a thyroidectomy will need to take daily thyroid hormone (levothyroxine) pills. If RAI treatment is planned, the start of thyroid hormone therapy may be delayed until the treatment is finished (usually about 6 to 12 weeks after surgery).

Recurrent cancer: Treatment of cancer that comes back after initial treatment depends mainly on where the cancer is growing, although other factors may be important as well. The recurrence might be found by either blood tests or imaging tests such as ultrasound or radioiodine scans.

If cancer comes back in the neck, an ultrasound-guided biopsy is done to confirm that it is cancer. If the tumor appears to be resectable (removable), surgery is often used. If the cancer shows up on a radioiodine scan (meaning the cells are taking up iodine), radioactive iodine (RAI) therapy may be used, either alone or with surgery. If the cancer does not show up on the radioiodine scan but is found by other imaging tests (such as an MRI or PET scan), external radiation may be used.

Targeted therapy drugs such as lenvatinib (Lenvima) or sorafenib (Nexavar) may be tried if the cancer has spread to several places and RAI and other treatments are not helpful. If these drugs are no longer working, cabozantinib (Cabometyx) might be an option. Other targeted drugs might be helpful as well, especially if the cancer cells have changes in certain genes (such as the RET or NTRK genes). Because these cancers can be hard to treat, taking part in a clinical trial of newer treatments is another choice.

Follicular and Hürthle cell cancers

Often, it isn’t clear that a tumor is a follicular cancer based on FNA biopsy. If the biopsy results are unclear, they might list “follicular neoplasm” as a diagnosis. Only about 2 of every 10 follicular neoplasms will actually turn out to be cancer, so the next step is usually surgery to remove the half of the thyroid gland that has the tumor (a lobectomy).

If the tumor turns out to be a follicular cancer, a second operation to remove the rest of the thyroid is usually needed (this is called a completion thyroidectomy). If the patient is only willing to have one operation, the doctor may just remove the whole thyroid gland in the first surgery. Still, for most patients, this isn’t really needed.

If there are signs the cancer has spread before surgery, the tumor must be a cancer and so a thyroidectomy will be done.

Hürthle (Hurthle) cell cancer can also be hard to diagnose based on FNA biopsy. Tumors suspected of being Hürthle cell cancer are often treated like follicular neoplasms. A lobectomy is usually done first. If cancer is confirmed, a completion thyroidectomy is done. A thyroidectomy may be done as the first surgery if there are signs the cancer has spread or if the patient wants to avoid having more surgery later.

As with papillary cancer, some lymph nodes usually are removed and tested for cancer. If cancer has spread to lymph nodes, a central compartment or modified neck dissection (surgical removal of lymph nodes from the neck) may be done. Because the thyroid is removed, patients will need to take thyroid hormone therapy as well, although it is often not started right away.

Radioiodine scanning is usually done after surgery to look for areas still taking up iodine. Spread to nearby lymph nodes and to distant sites that shows up on the scan can be treated by radioactive iodine (RAI). For cancers that don’t take up iodine, external beam radiation therapy may help treat the tumor or prevent it from growing back in the neck.

Cancer that has spread to distant areas such as the lungs or liver may need to be treated with external beam radiation therapy, or with targeted therapy drugs such as lenvatinib (Lenvima) or sorafenib (Nexavar) if they do not respond to RAI. Other targeted drugs might be helpful as well, especially if the cancer cells have changes in certain genes (such as the RET or NTRK genes). Another option is taking part in a clinical trial of newer treatments or chemotherapy

Recurrent cancer: Treatment of cancer that comes back after initial therapy depends mainly on where the cancer is growing, although other factors may be important as well. The recurrence might be found by either blood tests or imaging tests such as ultrasound or radioiodine scans.

If cancer comes back in the neck, an ultrasound-guided biopsy is first done to confirm that it is cancer. If the tumor appears to be resectable (removable), surgery is often used. If the cancer shows up on a radioiodine scan (meaning the cells are taking up iodine), radioactive iodine (RAI) therapy may be used, either alone or with surgery. If the cancer does not show up on the radioiodine scan but is found by other imaging tests (such as an MRI or PET scan), external radiation may be used.

Targeted therapy with drugs such as lenvatinib (Lenvima) or sorafenib (Nexavar) is often tried first if the cancer has spread to several places and RAI was not helpful. If these drugs are no longer working, cabozantinib (Cabometyx) might be an option. Other targeted drugs might be helpful as well, especially if the cancer cells have changes in certain genes (such as the RET or NTRK genes). Chemotherapy and taking part in a clinical trial of newer treatments are also options.

Medullary thyroid cancer

Most doctors advise that patients diagnosed with medullary thyroid cancer (MTC) be tested for other tumors that are typically seen in patients with the MEN 2 syndromes (see Thyroid Cancer Risk Factors), such as pheochromocytoma and parathyroid tumors. Screening for pheochromocytoma is particularly important, because anesthesia and surgery can be extremely dangerous when these tumors are present. If surgeons and anesthesiologists know about such tumors ahead of time, they can treat the patient with medicines before and during surgery to make surgery safe.

Stages I and II: Total thyroidectomy is the main treatment for MTC and often cures patients with stage I or stage II MTC. Nearby lymph nodes are usually removed as well. Because the thyroid gland is removed, thyroid hormone therapy is needed after surgery. For MTC, thyroid hormone therapy is meant to provide enough hormone to keep the patient healthy, but it does not reduce the risk that the cancer will come back. Because MTC cells do not take up radioactive iodine, there is no role for radioactive iodine therapy in treating MTC.

Stages III and IV: Surgery is the same as for stages I and II (usually after screening for MEN 2 syndrome and pheochromocytoma). Thyroid hormone therapy is given afterward. When the tumor is extensive and invades many nearby tissues or cannot be completely removed, external beam radiation therapy may be given after surgery to try to reduce the chance of recurrence in the neck.

For cancers that have spread to distant parts of the body, surgery, radiation therapy, or similar treatments may be used if possible. If these treatments can’t be used, targeted drugs such as vandetanib (Caprelsa) or cabozantinib (Cometriq) may be tried. Other targeted drugs might be helpful as well, especially if the cancer cells have changes in certain genes (such as the RET gene). Chemotherapy may be another option. Because these cancers can be hard to treat, another option is taking part in a clinical trial of newer treatments.

Recurrent cancer: If the cancer recurs in the neck or elsewhere, surgery, external radiation therapy, targeted therapy drugs (such as vandetanib or cabozantinib), or chemotherapy may be needed. Clinical trials of new treatments may also be an option.

Genetic testing in medullary thyroid cancer: If you are told that you have MTC, even if you are the first one in the family to be diagnosed with this disease, ask your doctor about genetic counseling and testing. Genetic testing can check your cells for mutations in the RET gene, which is seen in people with familial MTC and the MEN 2 syndromes.

If you have one of these mutations, it’s important that close family members (children, brothers, sisters, and parents) be tested as well. Because almost all children and adults with mutations in this gene will develop MTC at some time, most doctors agree that anyone who has a RET gene mutation should have their thyroid removed to prevent MTC soon after getting the test results. This includes children, since some hereditary forms of MTC affect children and pre-teens. Total thyroidectomy can prevent this cancer in people with RET mutations who have not yet developed it. In this case, lifelong thyroid hormone replacement will be needed.

Anaplastic cancer

Because this cancer is already widespread when it is diagnosed, surgery is often not helpful as treatment. If the cancer is confined to the area around the thyroid, which is rare, the entire thyroid and nearby lymph nodes may be removed. The goal of surgery is to remove as much cancer in the neck area as possible, ideally leaving no cancer behind. Because of the way anaplastic cancer spreads, this is often difficult or impossible.

Radioactive iodine treatment is not used because it does not work in this cancer.

External beam radiation therapy may be used alone or combined with chemotherapy:

• To try to shrink the cancer before surgery to increase the chance of removing it completely
• After surgery to try to control any cancer that remains in the neck
• When the tumor is too large or widespread to be treated by surgery

If the cancer is causing (or may eventually cause) trouble breathing, a hole may be placed surgically in the front of the neck and into the windpipe to bypass the tumor and allow the patient to breathe more comfortably. This hole is called a tracheostomy.

For cancers that have spread, chemotherapy alone can be used. If the cancer cells have changes in certain genes, treatment with targeted drugs might be helpful:

• Dabrafenib (Tafinlar) and trametinib (Mekinist) can be used to treat cancers with certain BRAF gene changes.
• Selpercatinib (Retevmo) can be used to treat cancers with certain RET gene changes.
• Larotrectinib (Vitrakvi) or entrectinib (Rozlytrek) can be used to treat cancers with NTRK gene changes.

Because these cancers can be hard to treat, clinical trials of newer treatments are an option as well.