Treatment
Treatment options for thyroid cancer vary depending on the type of thyroid cancer, the stage of the disease, and the patient's age and general health. The most common treatments are surgery to remove the thyroid (thyroidectomy), followed by thyroid hormone therapy and possibly radioactive iodine therapy. The doctor may recommend any of the following procedures to treat thyroid cancer, depending on the size of the tumor and the stage of the disease:
Lobectomy
Surgery is the main treatment for most cases of thyroid cancer. In a lobectomy, the surgeon removes only the side (lobe) of the thyroid where the tumor is located. Lobectomies are occasionally used to treat small papillary or follicular thyroid tumors that have not spread outside of the thyroid. Following this surgery, the patient may need to take daily thyroid hormone pills. The surgeon may also remove nearby cancerous lymph nodes in the neck (lymphadenectomy).
Thyroidectomy
In a thyroidectomy, the surgeon removes the entire thyroid gland. After surgery, the patient will need to take daily thyroid hormone pills. The surgeon may also remove nearby cancerous lymph nodes in the neck (lymphadenectomy).
Radioactive Therapy
The thyroid gland and cells of many papillary and follicular thyroid cancers absorb iodine. In this procedure, the patient ingests high doses of radioactive iodine, which collects in the thyroid and destroys cancer cells. This substance also collects in thyroid cancer cells in other parts of the body. Doctors often use this treatment after surgery, to target any remaining cancer cells in the body. This treatment can destroy thyroid cancer cells with a low risk of harming other parts of the body, and has even been shown to treat metastases in different parts of the body.
Thyroid Hormone Therapy
Patients who have undergone surgery to remove the thyroid gland will also need to take daily thyroid hormones to replace the hormones the thyroid gland used to produce. The doctor may also recommend taking these pills to treat thyroid cancer in some cases. High levels of the thyroid hormone prevent the pituitary gland from producing too much TSH, a hormone that can stimulate the growth of thyroid cancer cells (papillary and follicular).
External Radiation Therapy
Radiation therapy uses waves of high-energy rays produced by a machine to target and kill cancer cells. Radiation therapy is not often used to treat papillary and follicular thyroid cancer, as these types of thyroid cancer respond much better to radioactive iodine therapy. But, this treatment can help patients with tumors that cannot be fully removed by surgery, and for those with metastases to bones or the brain. External radiation therapy is also occasionally used for medullary thyroid cancer, which does not absorb iodine. It may also be used to treat distant metastases and shrink tumors when radioiodine therapy is not an option. Finally, it is often used in patients with anaplastic thyroid cancer, combined with chemotherapy.
Chemotherapy
Chemotherapy is the use of drugs to target rapidly growing cells in an effort to destroy cancer cells. Most of these medications are given through the vein (intravenously) and some are given by mouth (orally). Chemotherapy is rarely used to treat thyroid cancer, but may be used to treat more widespread cases of the disease. It is also commonly part of the treatment for anaplastic cancer.
Targeted Therapy
Some types of thyroid cancer have activated proteins that can fuel cancer cell growth. Targeted therapy inhibits these proteins and prevents them from stimulating the growth of malignant cells. In the past decade, there has been major progress leading to the introduction of different classes of drugs to treat thyroid cancer. Some of these oral chemotherapy targeted drug target primarily the blood supply feeding the tumor and often have many targets (multitarget kinase inhibitors). Two drugs (vandetinib and cabozantinib) have been approved in the treatment of medullary thyroid cancer, and therapy is appropriate for patients with large amounts of progressive metastatic disease. Sorafenib, lenvatinib, and cabozantinib have been approved for papillary or follicular thyroid cancer in patients with large amounts of progressive metastatic disease that does not respond to radioactive iodine or may have failed prior targeted therapy. Other drugs target particular genetic mutations that may exist in thyroid cancer cells. For example, tumors with underlying BRAF mutation can be treated with dabrafenib (BRAF inhibitor) alone or in combination with trametinib (MEK inhibitor). Tumors with RET gene alterations can be treated with RET inhibitors ( selpercatinib or pralsetinib), while tumors with NTRK altrations can be treated with NTRK inhibitors such as larotrectinib.
Immunotherapy
Immunotherapy is a new cancer treatment that stimulates the body's immune system to attack cancer cells. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or biologic therapy. The rule of immunotherapy in thyroid cancer management is still evolving.
Clinical Trials
Clinical trials allow patients to try a new treatment before it is available to the general public. In some cases, this may be a new drug that has not been used in humans before, or it may be a drug or drug combination that is not currently used for that specific type of cancer. Early phase clinical trials are often used to test side effects of a drug or drug combination, while later phase clinical trials are used to see how effective a new treatment might be for a certain type of cancer. Clinical trials allow doctors and researchers to improve the treatment of cancers with possibly more effective therapies. A clinical trial may be a new, groundbreaking drug or it may have no effect. It is important to talk with your doctor about the pros and cons of clinical trials for your particular situation.
