Medically reviewed by Dr. C.H. Weaver M.D. 12/2018
An awareness of the risk factors for developing thyroid cancer can help you and your healthcare team assess your risk. Individuals at a higher risk of developing thyroid cancer may wish to discuss with their physician more aggressive screening measures.
- Age Papillary and follicular thyroid cancers can develop at any age but are more common in young adulthood. Sporadic medullary thyroid cancer usually occurs in adults. Multiple endocrine neoplasia (MEN) type 2 syndromes and familial medullary cancer also occur in adults but can affect children and infants as well.
- Race White Americans have a greater risk of developing thyroid cancer than Black Americans.
- Radiation People exposed to high levels of radiation are much more likely than others to develop papillary or follicular thyroid cancer. One significant source of radiation exposure can be treatment with X-rays. Between the 1920s and the 1950s, doctors used high-dose X-rays to treat children who had acne, enlarged tonsils, and other problems affecting the head and the neck. Scientists later discovered that some people who had received this kind of treatment developed thyroid cancer.
- Family history of medullary thyroid cancer Medullary thyroid cancer sometimes runs in families. A change in a gene called RET can be passed from parent to child. Nearly everyone with the changed RET gene develops medullary thyroid cancer. The disease occurs alone as familial medullary thyroid cancer or with other cancers as MEN syndrome. A blood test can detect the changed RET gene. If it’s found in a person with medullary thyroid cancer, the doctor may suggest that family members be tested. For those who have the changed gene, the doctor may recommend frequent lab tests or surgery to remove the thyroid before cancer develops.
- Personal history People with a goiter or benign thyroid nodules have an increased risk of thyroid cancer.
- Being female In the United States, women are almost three times as likely as men to develop thyroid cancer.
- Inherited conditions Papillary thyroid cancer risk increases with Gardner’s syndrome or familial adenomatous polyposis—genetic disorders where precancerous polyps develop throughout the colon and the upper intestine. Having Cowden disease, a rare, inherited disorder that causes lesions on the face, hands, and feet and inside the mouth, can also increase the risk of developing thyroid cancer.
- Iodine Scientists are currently studying the possible risk factors that iodine might present (whether too little iodine in the diet might increase the risk of follicular thyroid cancer and whether too much may increase the risk of papillary thyroid cancer).1