What Causes Thyroid Cancer, and How to Prevent It

Causes of Thyroid Cancer

It is not known exactly what causes thyroid cancer, or the growth of thyroid nodules. What is known are the risk factors that can increase the chances of contracting the disease:

• Being exposed to high levels of radiation, especially to the head and neck area – e.g. as a result of radiation therapy;

• A family history of thyroid nodules;
• Being female, as females are more prone to contracting thyroid cancer than males;
• A diet low in iodine;
• Inflammatory thyroid disorders, including goitre (enlargement of the thyroid gland), hypothyroidism, and Hashimoto’s thyroiditis (which is an autoimmune condition that causes hypothyroidism);
• Inherited genetic conditions such as familial medullary thyroid cancer, multiple endocrine neoplasia, Cowden’s syndrome and familial adenomatous polyposis.

How to Prevent Thyroid Cancer

Just as there is no known definitive causes of thyroid cancer, there is unfortunately no known preventive measure that guarantees avoidance of thyroid cancer. What we can do it to reduce the risk factors that contribute to the likelihood of contracting the disease. These include:

• Avoiding exposure to radiation around the neck area (including those from medical procedures), particularly for young children. It is not clear how much imaging tests like X-Rays and CT scans might raise the risk of thyroid cancer to children, as the radiation levels are not that high. While any increased risk is likely to be small, children should nonetheless not undergo these tests unless absolutely required, to be on the safe side. If carried out, they should be done using the lowest level of radiation that can still provide a sufficiently clear picture.
• People with inherited genetic conditions that increase the risk of medullary thyroid cancer can consult with a genetic counsellor.