A risk factor is anything that increases a person's chance of getting a disease. Different diseases have different risk factors. Some risk factors can be controlled with lifestyle changes. Other risk factors cannot be changed.
Patients with anaplastic thyroid cancer are usually past age 65 years. Many patients will have a history of thyroid cancer in the past or a long-standing goiter. A history of head and neck radiation or exposure to radioactive materials in one's past may increase the risk for ATC.
Having one or more of the above risk factors does not mean that you will develop anaplastic thyroid cancer. Understanding your risk factors will help you determine, what, if any, precautions and possible screening options you should consider.