Treatment for Thyroid Cancer

The stage of thyroid cancer helps to determine the exact course of treatment. In general, if a needle biopsy and/or other diagnostic tests reveals that a thyroid nodule is benign, the doctor will likely recommend that thyroid function is tested regularly, and the nodule is watched for growth. If the size of a nodule increases, another needle biopsy will likely be performed.

If a benign thyroid nodule never changes, treatment may not be necessary. However, if a biopsy and/or other diagnostic tests reveals that a thyroid nodule is malignant, treatment is recommended.

Surgery to Treat Thyroid Cancer

If a thyroid tumor is malignant, surgery to remove it along with some or all of the thyroid gland usually is performed. This surgery, in general, is called thyroidectomy.

  • If the tumor is smaller than 1 cm, there is no evidence of cancer in the lymph nodes or elsewhere, only the affected side of the gland may be removed. This procedure is called a lobectomy.
  • If the tumor is larger than 1 cm, or if there are signs of cancer in the lymph nodes, the entire thyroid gland usually is removed. If the cancer has spread to the lymph nodes, they will also be removed during surgery.

Thyroidectomy usually requires a 3–7 day hospital stay. Choosing a qualified surgeon is highly recommended to help reduce the risk for complications.

Complications, such as temporary or permanent hoarseness or loss of voice, may occur, but are generally rare. Possible complications include damage to the parathyroid gland (causing muscle spasms and numbness), excessive bleeding, infection, and blood clots in the neck.

Thyroid Hormone Therapy to Treat Thyroid Cancer

If part or all of a thyroid gland is removed, hormone therapy medication is necessary to replace the thyroid gland hormones that can no longer be produced. In this case, a synthetic form of thyroid hormone must be taken daily for life. This type of hormone therapy is considered safe and causes few side effects. If tiredness, nervousness, weight loss or gain, or an increased heart rate occurs, the dosage of the hormone is adjusted.

Radioactive Iodine Therapy to Treat Thyroid Cancer

If papillary thyroid cancer or follicular thyroid cancer has spread to other parts of the body, or in patients who have a tumor larger than 1 cm and who are over age 45, radioactive iodine therapy (also called radioiodine ablation) is usually recommended. Radioactive iodine is given in the form of a capsule and is absorbed specifically into thyroid tissue that was not removed through surgery and any thyroid cancer cells that have migrated to other parts of the body.

The radioactivity destroys the remaining thyroid tissue with little or no harm to surrounding cells. Side effects from this treatment are rare, and include neck tenderness, nausea, dry mouth, irregular menstrual periods in women, and infertility in men. There may also be a slight risk of developing leukemia, although there is conflicting evidence on the likelihood of this possibility.

Radiation to Treat Thyroid Cancer

In cases of anaplastic thyroid cancer or late-stage thyroid cancer, external beam radiation therapy may be recommended. In this treatment, a beam of radiation is focused on the affected area to destroy the cancer cells, with the goal of slowing or stopping the spread of the cancer. Unlike, radioiodine therapy, this type of radiation may destroy nearby healthy cells and may cause side effects such as fatigue and sunburn-like skin changes.

Chemotherapy to Treat Thyroid Cancer

Anaplastic thyroid cancer and late-stage thyroid cancer may be treated using chemotherapy, which involves the use of powerful drugs that destroy rapidly growing cancer cells.

There are many different kinds of chemotherapy drugs and they may be administered in pill form, by injection, or intravenously (through an IV). Side effects include hair loss, nausea, fatigue, mouth sores, and reduced immunity.

Some patients must limit their activities, change their diets, and/or stop working during chemotherapy, and other patients are able to continue to work and carry out their normal routines. Most side effects can be effectively managed.

Drugs like vandetanib (approved by the FDA in April 2011) and cabozantinib (Cometriq; approved in November 2012) may be used to treat late stage medullary thyroid cancer. (This relatively rare type of thyroid cancer develops in the C cells of the thyroid.)

Vandetanib is an oral medication that is administered daily and inhibits the cancer's ability to grow. Side effects include nausea, abdominal pain, diarrhea, rash, high blood pressure, headache, fatigue and loss of appetite. Vandetanib may cause serious side effects, such as breathing complications, irregular heart beat, heart failure and blood infection (sepsis).

Cometriq blocks abnormal kinase proteins involved in the development and growth of medullary cancer cells. Patients on this medication should not eat for at least 2 hours before and 1 hour after taking the drug. Side effects include diarrhea, nausea, weight loss, mouth sores, and others.

In February 2015, the FDA approved lenvatinib (Lenvima) to treat progressive, differentiated thyroid cancer that progresses in spite of radioactive iodine therapy. In clinical trials, patients who received Lenvima experienced a reduction in tumor size and increased progression-free survival. This medication can cause serious side effects.

Thyroid Cancer Follow Up

After treatment, it is important to make sure that no cancer cells remain and to monitor thyroid hormone levels regularly. Thyroid scans are used to detect any remaining thyroid cells in the body after surgery and treatment. Any residual cells will take up the radioactive iodine and be detected. This test may be performed at regular intervals to ensure that all thyroid cells have been removed and no cancerous thyroid cells remain.

Thyroid scans require a high level of thyroid stimulating hormone (TSH) in the blood. In the past, this was achieved by inducing hypothyroidism, but because this is an uncomfortable condition, a synthetic version of TSH can now be used to perform this test.

Testing the blood for thyroglobulin helps ensure that all thyroid gland tissue has been removed from the body. If all thyroid tissue is gone, there will be little or no thyroglobulin in the blood. This test also requires high TSH levels.

Thyroid Cancer Prognosis

In general, thyroid cancer is one of the most treatable types of cancer. The five-year survival rate for stage I and stage II papillary, follicular, and medullary thyroid cancer is about 97 percent or greater. The prognosis for stage III cancer of these types is also quite high. Unfortunately, the prognosis for anaplastic thyroid cancer is much less hopeful—with a five-year survival rate of about 9 percent.

Thyroid Cancer Prevention

Thyroid cancer cannot be prevented in every case. To reduce the risk:

  • Ask about potassium iodide tablets. If taken as directed just before or right after exposure to radioactive fallout, these tablets can help protect against a certain type of radioactive material. (As part of homeland security measures, people who live within 10 miles of a nuclear power plant should have these tablets on hand in case of a terrorism incident.)
  • A healthy lifestyle: eating a nutritious diet, getting proper exercise, and maintaining a healthy weight can help reduce the risk for many types of cancer.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 31 Oct 2006

Last Modified: 06 Oct 2015