However a family history of thyroid cancer and/or radiation exposure, especially in childhood, is associated with an increased risk.
X-ray irradiation of the head and neck region - especially during childhood and adolescence – increases the risk of developing thyroid cancer. People who have been exposed to high levels of radiation, e.g. following a nuclear reactor disaster, are also at increased risk of developing thyroid cancer. In this situation, the risk of cancer increases with higher doses of radiation exposure, with children and adolescents being particularly vulnerable.
Iodine deficiency over a long period can increase the risk of developing thyroid cancer. Patients who suffer from an enlarged thyroid ("goitre") due to iodine deficiency particularly over a long period, have an increased risk of developing thyroid cancer.