Chemotherapy for Thyroid Cancer

Chemotherapy (chemo) is the use of anti-cancer drugs that are injected into a vein or are taken by mouth. Chemo drugs enter the bloodstream and travel throughout the body to reach and destroy cancer cells.

Chemotherapy is seldom helpful for most types of thyroid cancer, but fortunately it isn’t needed in most cases.

When might chemotherapy be used for thyroid cancer?

For anaplastic thyroid cancer, chemotherapy is often combined with external beam radiation therapy. It’s also sometimes used for other types of thyroid cancer, when the cancer has spread and surgery and radiation therapy aren’t options. However, targeted drugs are usually tried first, as they are more likely to be helpful.

Which chemo drugs are used to treat thyroid cancer?

Doctors give chemo in cycles, with each period of treatment followed by a rest period to allow the body time to recover. Chemo cycles generally last a few weeks.

The chemo drugs most often used to treat thyroid cancer include:

• Dacarbazine
• Vincristine
• Cyclophosphamide
• Doxorubicin
• Streptozocin
• 5-Fluorouracil
• Paclitaxel
• Docetaxel
• Cisplatin
• Carboplatin

Depending on the type of thyroid cancer and other factors, 2 chemo drugs are sometimes combined.

Most of these drugs are given as an infusion into a vein (IV), although some can be taken as pills.

Possible side effects of chemo for thyroid cancer

Chemo drugs can also affect other cells in the body, which can lead to side effects.

The side effects of chemo depend on which drugs are given, the doses used, and the length of treatment. Common side effects of chemo include:

• Hair loss
• Mouth sores
• Loss of appetite
• Nausea and vomiting
• Diarrhea or constipation
• Increased chance of infections (from having too few white blood cells)
• Easy bruising or bleeding (from having too few blood platelets)
• Fatigue (from having too few red blood cells)

These side effects usually go away after treatment is finished. There are often ways to lessen them. For example, drugs can be given to help prevent or reduce nausea and vomiting.

Some chemo drugs may have other side effects. For example:

• Doxorubicin (one of the most common chemo drugs for thyroid cancer) can affect heart function. If you are getting doxorubicin, your doctor will check your heart regularly using tests such as echocardiograms.
• Drugs like cisplatin, carboplatin, and paclitaxel can damage nerves. This sometimes leads to symptoms (mainly in the hands and feet) such as pain, burning or tingling, sensitivity to cold or heat, or weakness. This is called peripheral neuropathy.

Ask your cancer care team about the side effects your chemo drugs may cause.