What is thyroid cancer?
Thyroid cancer develops in the thyroid, a small butterfly-shaped gland at the base of your neck. This gland produces hormones that regulate your metabolism (how your body uses energy). Thyroid hormones also help control your body temperature, blood pressure and heart rate. Thyroid cancer, a type of endocrine cancer, is generally highly treatable with an excellent cure rate.
What is the thyroid gland?
Your thyroid gland is one of many glands that make up your endocrine system. Endocrine glands release hormones that control different bodily functions.
The pituitary gland in your brain controls your thyroid gland and other endocrine glands. It releases thyroid-stimulating hormone (TSH). As the name suggests, TSH stimulates your thyroid gland to produce thyroid hormone.
Your thyroid needs iodine, a mineral, to make these hormones. Iodine-rich foods include cod, tuna, dairy products, whole-grain bread and iodized salt.
Where is your thyroid gland?
The thumb-sized thyroid gland sits at the base of your neck, in front of your windpipe and below your Adam’s apple. The thyroid gland resembles a butterfly. A bridge of tissue connects the right and left lobes, or sides.
How common is thyroid cancer?
Close to 53,000 Americans receive a diagnosis of thyroid cancer every year. Treatments for most thyroid cancers are very successful. Still, about 2,000 people die from the disease every year.
Who might have thyroid cancer?
Women are three times more likely than men to get thyroid cancer. The disease is commonly diagnosed in women in their 40s and 50s, and men in their 60s and 70s. Even children can develop the disease. Risk factors include:
- Enlarged thyroid (goiter).
- Family history of thyroid disease or thyroid cancer.
- Thyroiditis (inflammation of the thyroid gland).
- Gene mutations (changes) that cause endocrine diseases, such as multiple endocrine neoplasia type 2A (MEN2A) or type 2B (MEN2B) syndrome.
- Low iodine intake.
- Obesity (high body mass index).
- Radiation therapy for head and neck cancer, especially during childhood.
- Exposure to radioactive fallout from nuclear weapons or a power plant accident.
What are the types of thyroid cancer?
Thyroid cancer is classified based on the type of cells from which the cancer grows. Thyroid cancer types include:
- Papillary: Up to 80% of all thyroid cancers are papillary. This cancer type grows slowly. Although papillary thyroid cancer often spreads to lymph nodes in the neck, the disease responds very well to treatment. Papillary thyroid cancer is highly curable and rarely fatal.
- Follicular: Follicular thyroid cancer accounts for up to 15% of thyroid cancer diagnoses. This cancer is more likely to spread to bones and organs, like the lungs. Metastatic cancer (cancer that spreads) can be more challenging to treat.
- Medullary: About 2% of thyroid cancers are medullary. A quarter of people with medullary thyroid cancer have a family history of the disease. A faulty gene (genetic mutation) may be to blame.
- Anaplastic: This aggressive thyroid cancer is the hardest type to treat. It can grow quickly and often spreads into surrounding tissue and other parts of the body. This rare cancer type accounts for about 2% of thyroid cancer diagnoses.
What causes thyroid cancer?
Experts aren’t sure why some cells become cancerous (malignant) and attack the thyroid. Certain factors, such as radiation exposure, a diet low in iodine and faulty genes can increase risk.
What are the symptoms of thyroid cancer?
You or your healthcare provider might feel a lump or growth in your neck called a thyroid nodule. Don’t panic if you have a thyroid nodule. Most nodules are benign (not cancer). Only about three out of 20 thyroid nodules turn out to be cancerous (malignant).
Other signs of thyroid cancer include: