What Are the Causes of Thyroid Cancer?
No one knows what causes thyroid cancer, but experts have identified many risk factors: • Exposure to large amounts of radiation (either from the environment or in those who have had radiation treatment for medical problems in the head and neck, such as acne or fungal infections of the face). The cancer may not occur until 20 years or longer after radiation treatment. • Heredity (particularly for medullary thyroid cancer). • Sex. Cancer of the thyroid is more common in women than in men.