Risk factors

Factors that may increase the risk of thyroid cancer include:

• Female sex. Thyroid cancer occurs more often in women than in men.
• Exposure to high levels of radiation. Radiation therapy treatments to the head and neck increase the risk of thyroid cancer.
• Certain inherited genetic syndromes. Genetic syndromes that increase the risk of thyroid cancer include familial medullary thyroid cancer, multiple endocrine neoplasia, Cowden's syndrome and familial adenomatous polyposis.