It is difficult for doctors to determine why one person develops a thyroid cancer and another does not. However, research has provided evidence showing that people with certain risk factors are more likely to develop the disease. The following risk factors have been associated with an increased chance of developing thyroid cancer.
Radiation: Individuals exposed to radiation are more likely to develop papillary or follicular thyroid cancer.
Family history of medullary thyroid cancer: Medullary thyroid cancermay be passed down from parent to child through a change on the RET gene. Nearly everyone with this changed gene develops the disease, which may occur alone or with other cancers such as multiple endocrine neoplasia (MEN) disorder.
Family/personal history of goiters or colon growths: Some people with a family history &/or personal history of multiple thyroid nodules are at greater risk of developing papillary thyroid cancer.
Gender: Females are three times more likely than males to develop thyroid cancer.
Age: Thyroid cancer most commonly occurs in people over the age of 45. Anaplastic thyroid cancer mainly occurs in people over the age of 60.
Iodine: Scientists are still researching iodine as a potential risk for developing thyroid cancer. Studies have suggested that a diet too low in iodine (a substance found in shellfish, iodized salt) may increase the risk of developing follicular thyroid cancer. Other studies have shown that a diet too rich in iodine may increase the risk of papillary thyroid cancer. More research is necessary to determine whether or not iodine is a risk factor for thyroid cancer.
The more risk factors a person has, the greater one’s chance of developing thyroid cancer. However, many people with known risk factors for thyroid cancer do not develop the disease. People with a family history of the disease or those who think they may be at risk should discuss this concern with their doctor. Your doctor may be able to suggest genetic blood tests and other ways to reduce you and your family’s risk of developing thyroid cancer.
Most early thyroid cancers are discovered when patients ask their doctors about lumps or nodules they have noticed. If you believe you have symptoms such as a lump or other abnormal growth on your neck, it is recommended that you see a doctor as soon as possible to have it examined. Some cancer professionals recommend that people perform a self examination of their necks twice yearly to search for any lumps.
People with a family history of medullary thyroid carcinoma (MTC) with or without type 2 multiple endocrine neoplasia (MEN 2) may be at very high risk for developing this cancer. Most doctors recommend genetic testing for these people when they are young to see if they carry the gene for MTC.