The American Cancer Society recommends the following:

Most people with thyroid cancer have no known risk factors, so it is not possible to prevent most cases of this disease.

Radiation exposure, especially in childhood, is a known risk factor for thyroid cancer. Because of this, doctors no longer use radiation treatment for less serious diseases. In general, it is a good idea for children to avoid any x-rays that aren't necessary.

Blood tests are available to test for the gene mutations found in familial medullary thyroid carcinoma (MTC). Because of this, most of the familial cases of MTC can be prevented or treated early by removing the thyroid gland. Once the disease is discovered in a family, the rest of the family members can be tested for the mutated gene.

If you have a family history of MTC, it is important that you see a doctor who is familiar with the latest advances in genetic counseling and genetic testing for this disease. Removing the thyroid gland in children who carry the abnormal gene will prevent a cancer that might otherwise be fatal.