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Thyroid Cancer Chemotherapy and Targeted Therapy

Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy is a systemic therapy because the drugs travel through the body in the bloodstream. Chemotherapy is not a common treatment for thyroid cancer. It is sometimes given in combination with radiation to try to increase its effectiveness.

Photo of intravenous drug bag

Chemotherapy is given in cycles. A person will be treated for a period of time, and will then have time to recover from the side effects. This cycle will continue throughout the treatment. Most patients have chemotherapy in an outpatient part of the hospital, at the doctor's office, or at home. Depending on which drugs are given and the person's general health, however, the patient may need to stay in the hospital during treatment.

Unfortunately, chemotherapy for thyroid cancer has not been shown to be very effective, although it is sometimes used to treat anaplastic thyroid cancer, or advanced thyroid cancers if other treatments are no longer working. Currently, the most effective drug, doxorubicin, is still much less effective than surgery and RAI (radioactive iodine therapy).

As research has progressed, the development of newer targeted therapies to replace standard chemotherapy drugs has been a focus. Targeted therapies are medications that are designed to specifically turn off cellular mechanisms that cancer cells use to grow and to spread, rather than targeting all rapidly growing cells like chemotherapy does. A number of treatments, particularly with a group of drugs called tyrosine kinase inhibitors, have shown benefit in clinical trials of differentiated and medullary thyroid cancers, though not in anaplastic thyroid cancer. These drugs are expected to rapidly replace efforts to use chemotherapy in widespread thyroid cancers unresponsive to radioactive iodine. 

It is normal for patients to be overwhelmed with the information they receive from their doctors. It is important that they take the time to gather as much information as possible.

Side effects of chemotherapy

Chemotherapy attacks cells that are dividing quickly, including normal cells as well as cancer cells. Normal quickly dividing cells can be found in the bone marrow, the hair follicles, and lining of the intestines and mouth. Chemotherapy attacking normal cells at the same time it is killing cancer cells, is a common cause for side effects. Side effects a patient may have depend on the type and amount of drug being taken. Common side effects of chemotherapy include nausea, vomiting, hair loss, mouth sores, diarrhea, low blood counts, and fatigue. Less often, serious side effects, such as infection, bleeding, or heart damage may occur.