Thyroid cancer is rare cancer occurring in the butterfly-shaped gland at the front of the throat. It is caused by the growth of cells in the gland that regulates heart rate, blood pressure, temperature, and metabolism. Less than 200,000 cases of thyroid cancer are reported in the U.S. each year, but the rate is increasing because of better diagnostic tools.
Thyroid cancer is thought to be caused by a combination of genetic and environmental factors. The condition occurs when cells in the thyroid develop changes in their DNA. These mutations push the cells to multiply rapidly, forming a tumor.
A cancerous thyroid tumor can invade healthy thyroid tissue, the lymph nodes, the parathyroid gland, and other body parts.
Researchers do not yet know what prompts the change in cellular DNA that signals the beginning of thyroid cancer.
Early thyroid cancer may not have noticeable symptoms, but as the disease progresses, symptoms can include:
- A lump that you can feel through the skin in the thyroid area of the neck
- A visible change in the size of the neck
- Swelling in the thyroid, or a goiter
- Changes in voice
- Difficulty swallowing
- Pain in your throat
- Swollen lymph nodes
- Symptoms of hyper- or hypothyroidism (hot/cold flashes, weight changes, changes in diet)
Experiencing any of these symptoms is a reason to make an appointment to see your healthcare provider.
Who Gets It
Doctors diagnose thyroid cancer after a series of tests and examinations. These include the following.
A Physical Exam
Your doctor will examine the neck area for changes to the thyroid, such as a lump or nodule, and may ask if your family has a history of thyroid cancers or if you have had radiation exposure. They may order future tests based on their findings.
A blood test can determine levels of thyroid hormone (TSH). Doctors may prescribe medications to regulate TSH levels if your thyroid hormone levels are abnormal.
An overactive thyroid (hyperthyroidism) or underactive thyroid (hypothyroidism) can be a cause for concern. Regulating TSH levels will boost thyroid health and combat problems ranging from fatigue to dry skin.
Blood tests for free T3 and T4 levels are also essential in determining thyroid levels, as the TSH only shows the total level altogether.
If thyroid nodules are detected or expected, doctors may want to perform ultrasound testing. Ultrasound uses high-frequency sound waves to create images of the body's inner workings. Thyroid imaging is performed by placing the ultrasound transducer at the base of the neck.
How to Prevent
What Research Says
Since most types of thyroid carcinoma are treated successfully, researchers from the National Cancer Institute are studying how patients can choose less-invasive thyroid cancer treatments such as ketogenic diets with fewer side effects. Diet can decrease slower-growing papillary cancer and follicular thyroid cancer tumors.
Cancer Council and American Cancer Society research show that some patients could get similar results with a lobectomy or by deferring surgery and monitoring cancer for signs of growth. However, large nodules (over 3cm in size) do often have to be surgically removed, as they are a higher risk.
Risk Factors for Thyroid Cancer
Risk factors for developing this rare form of cancer include the following.
Being a Woman
Thyroid cancer occurs more in women than men. Researchers think this is linked to the hormone estrogen. People who are assigned a female gender at birth have higher estrogen levels.
People who have been diagnosed with genetic syndromes such as Cowden syndrome and familial adenomatous polyposis are at a higher risk of thyroid cancer. Thyroid cancers can also run in families.
Exposure to high radiation levels through the environment or through treatment of head and neck cancer increases the risk of developing thyroid cancer.
How Can It Be Prevented?
Many people diagnosed with thyroid cancer have no risk factors for the disease. Since radiation exposure is a risk factor for thyroid cancer, doctors no longer use radiation as a treatment of less-serious illnesses. X-rays and other imaging use low doses of radiation that are not considered a thyroid cancer risk.
Families who think they have an increased risk of thyroid cancer can get a test for the familial medullary thyroid cancer gene (MTC). Those with the MTC gene can opt to have their thyroid removed to avoid a potentially fatal cancer.