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Thyroid Cancer

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In most cases, the specific causes of thyroid cancer are not known. However, there are risk factors associated with age, gender, genetics, and radiation exposure:

  • Gender – women are two to three times more likely than men to develop thyroid cancer.
  • Age – two-thirds of thyroid cancers are diagnosed in people between the age of 20 and 55.
  • Exposure to high doses of radiation – x-rays received during the course of routine medical care are not a risk for thyroid cancer. Exposures that may increase risk include childhood x-ray treatments that were practiced before the 1960s, x-ray treatment of breast cancer or Hodgkin disease, or exposure to nuclear disasters.
  • Family history – having a family history of medullary thyroid cancer, multiple endocrine neoplasia (MEN), goiters, or precancerous colon polyps increases the risk of developing thyroid cancer.
  • Genetics – for example, some cases of medullary thyroid cancer (MTC) are caused by a mutation in the RET gene. Individuals with this gene have a high risk of developing thyroid cancer. If you have a family history of MTC or multiple endocrine neoplasia (MEN), blood tests are available to look for the mutation.

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