A risk factor is anything that increases your chance of developing cancer. The following factors can increase your risk of developing thyroid cancer:
Radiation Exposure
Exposure to high levels of radiation may increase the risk of papillary and follicular thyroid cancers.
- X-ray treatments used before 1950 to treat children with acne, tonsillitis, and other head and neck problems may increase the risk of papillary and follicular thyroid cancers. (Today, routine diagnostic x-rays use very low doses of radiation.)
- People who have been treated with radiation therapy for Hodgkin's lymphoma or other forms of lymphoma in the head and neck are at an increased risk for developing papillary or follicular thyroid cancer.
Family History of Medullary Thyroid Cancer
Medullary thyroid cancer (MTC) sometimes runs in families. A change in a gene called RET may increase risk for MTC. This altered gene may be passed from parent to child. Nearly everyone with the altered RET gene develops MTC. The altered gene can be detected with a blood test. The disease occurs either alone as familial medullary thyroid cancer or with other cancers as multiple endocrine neoplasia (MEN) syndrome.
Family History of Goiters
A goiter is swelling or lump in the neck due to an enlarged thyroid gland. A goiter is not cancerous. A small number of people with a family history of having goiters are at risk for developing papillary thyroid cancer.
Family History of Colon Growths
A small number of people with a family history of having multiple growths on the inside of the colon are at risk for developing papillary thyroid cancer.
Being Female
Although it is unclear why, thyroid cancer occurs about three times more often in women than in men.
Diet Low in Iodine
Follicular thyroid cancers are more common in areas of the world where people's diets are low in iodine. A diet low in iodine may be more likely to increase the risk of papillary cancer if the person also is exposed to radioactivity. This risk factor does not play a significant role in the US, where iodine is plentiful.
