The thyroid is crucial for many different processes in the body. It helps control everything from your metabolism and weight to your heart rate and body temperature. This butterfly-shaped organ sits at the front of your neck, underneath your Adam’s apple. The thyroid’s main job is to create hormones — chemicals that travel around the body and affect the function of many different tissues. Thyroid cancer develops when cells in this gland begin growing out of control, forming a tumor.
How many people get thyroid cancer?
An estimated 43,800 people in the U.S. will develop thyroid cancer in 2022. Thyroid cancer accounts for about 2.3% of all cancers. Globally, more than 586,000 cases of thyroid cancers are diagnosed each year. Women are three times more likely to have this cancer than men.
Symptoms of thyroid cancer
If you have thyroid cancer, you may experience signs like:
- An enlarged thyroid gland, which may appear as a lump or mass in the middle of the neck.
- A swollen neck.
- Pain or difficulties when swallowing.
- Breathing problems.
- Voice changes or hoarseness.
These symptoms are more commonly caused by other conditions, and don’t necessarily indicate that you have cancer. However, you should talk to your doctor if you notice any of these health changes.
Types of thyroid cancer
Thyroid cancer is categorized based on which cells the tumor develops from. The thyroid gland contains two main types of cells: follicular cells and C cells.
If a thyroid tumor forms from follicular cells, it is called differentiated thyroid cancer (DTC). This is the most common type of thyroid cancer, accounting for 90 to 95% of thyroid cancer cases. Certain subtypes of DTC, such as papillary thyroid cancer and follicular thyroid cancer, tend to be easier to treat, while other subtypes like Hurthle cell thyroid cancer and poorly differentiated thyroid cancer are more aggressive and may require different treatment plans.
Medullary thyroid cancer (MTC) is cancer that develops from the C cells in the thyroid. This form of cancer is more likely to be caused by genetic changes that are passed down within families.
Anaplastic thyroid cancer consists of cells that look very abnormal and spread very quickly. Although this type of cancer is very aggressive, it is also rare, making up less than 1% of thyroid cancer cases.
What causes thyroid cancer?
Some factors can increase your chances of developing thyroid cancer. They include:
- Being a woman.
- Being between the ages of 25 and 65.
- Being of Asian descent.
- Having a history of radiation treatments to the neck.
- Being exposed to high levels of radiation due to a nuclear plant accident.
- Having people in your family who have experienced thyroid cancer.
- Having an enlarged thyroid, also called a goiter.
- Having genetic conditions like familial medullary thyroid cancer (FMTC).
Some people with thyroid cancer don’t have any risk factors, and most people with these characteristics will never develop this condition. However, these factors may increase your risk.
Thyroid cancer treatments
If you have thyroid cancer, your treatment will often begin with surgery. During this procedure, a doctor will remove all or part of your thyroid gland. If the tumor has spread to other tissues, such as the lymph nodes, these may also need to be removed.
Surgery may be followed by additional treatments. Radiation therapy, which uses high-energy beams or particles to kill cancer cells, may be an option. In some types of radiation therapy, a machine is used to direct beams towards the neck, where they can target the thyroid. Another radiation therapy option for thyroid cancer is using radioactive iodine, since thyroid cells are the only cells that absorb iodine. Radioactive iodine particles can find and kill thyroid cells located anywhere in the body.
Other thyroid cancer treatments may include:
- Chemotherapy — These drugs can destroy cancer cells or prevent them from growing.
- Targeted therapy — This category of medication, including tyrosine kinase inhibitors and protein kinase inhibitors, recognizes and blocks cancer cells while largely leaving the body’s normal cells alone.
- Thyroid hormone therapy — This type of treatment involves taking medications that stop the body from making thyroid-stimulating hormone (TSH), a molecule that encourages thyroid cancer cells to grow.
Thyroid cancer therapies prevent the body from making important hormones that help support health. As a result, you will likely have to regularly take thyroid hormone pills after undergoing these treatments.
How well do thyroid cancer treatments work?
People with thyroid cancer are often predicted to have good outcomes. About 98.4% of people with this condition are expected to survive at least five years or more, excluding other possible causes of death.
Several factors can affect how well your thyroid cancer can be treated, including your age and overall health, your tumor’s size, and whether the cancer has spread into nearby tissues or to more distant parts of the body. When thyroid cancer starts spreading, it can become more difficult to treat.
To learn more about your thyroid cancer treatments and predicted outlook, talk to your healthcare team. Your doctor knows about your own personal characteristics and can help you better understand what to expect.
- National Cancer Institute. Cancer Stat Facts: Thyroid Cancer.
- NCBI. Survival from Differentiated Thyroid Cancer: What Has Age Got to Do with It?
- World Health Organization International Agency for Research on Cancer. Thyroid.
- MedlinePlus. Thyroid Cancer.
- StatPearls. Thyroid Cancer.
Show all references
- Mayo Clinic. Thyroid Cancer: Symptoms & Causes.
- National Cancer Institute. Thyroid Cancer Treatment (Adult) (PDQ)-Patient Version.
- Office on Women’s Health. Thyroid Disease.