Risk Factors for Thyroid Cancer

A risk factor is something that raises a person's chances of getting a health problem. A person can have thyroid cancer with or without the risks below. The more risks a person has, the greater the chances of having thyroid cancer are.

Thyroid cancer is more common in people who are at least 40 years of age. Anaplastic thyroid cancer is more common in people who are at least 60 years of age.

While women are more likely to get thyroid cancer, men are more likely to get medullary thyroid cancer.

Other things that raise the risk of thyroid cancer are:

• Radiation exposure—especially to the head and neck. This is especially true for kids and teens. The exposure could be from cancer treatments or having a lot of CT scans. It can also be from radioactive fallout. Examples are nuclear accidents or exposures at the World Trade Center site.
• Family history—Thyroid cancer tends to run in families. The risk is higher if a parent or sibling had the cancer.
• Some gene changes passed through families—With medullary thyroid cancer
• Health issues such as:
  • Low iodine levels (follicular thyroid cancer)
  • History of thyroid cancer
  • Obesity
  • Acromegaly
  • Sjogren syndrome
  • Organ transplant

Thyroid cancer is also more common in people of Hawaiian and Polynesian descent.