There is no doubt that researchers are yet to do a lot of work to find the causes of thyroid cancer but that doesn’t mean we don’t know nothing about this type of cancer. One thing we know for sure is that two major factors contribute to this type of cancer i.e., having a family history of thyroid cancer and being exposed to radiation. We will look at both these factors individually and in more details below.
A family history of thyroid cancer is the biggest risk factor as is the case with most cancer. Patients who have cancer in their first degree relatives have higher risk of developing thyroid cancer compared to those who have a family history of thyroid cancer in their second and third degree relatives. Nearly 5% patients diagnosed with papillary thyroid cancer have a family history of thyroid cancer. Similarly, nearly 25% patients of medullary thyroid cancer also have someone in the family who had thyroid cancer. A quick test for genetic abnormality for people with a family history of thyroid cancer can help to determine the risk of cancer.
Exposure to radiation, especially to the head and neck area, can increase the risk of developing thyroid cancer. The sources of such radiation could be numerous. For example, patients could develop thyroid cancer if exposed to radiation through a medical treatment or environment. Let’s have a look at both these contributing factors separately.
In the first half of this century before antibiotics became available, radiation therapy was used to treat several benign diseases, such as acne, scalp ringworm, enlarged tonsils, enlarged thymus, enlarged lymph nodes in the neck as a result of tuberculosis, whooping cough, and keloid scars. In fact, over one million young Americans received x-ray treatments to the head or neck between 1920 and 1960. At the time, it was not known that the long term effects of this radiation therapy to the head and neck area would cause thyroid cancer (usually papillary thyroid cancer). When the association between radiation treatment and thyroid cancer was established, the use of this type of therapy was largely stopped.
Fortunately, thyroid cancers usually have a very slow growth rate, which allows patients time to consider their treatment alternatives. In fact, thyroid cancer may not develop for 30 to 50 years after the radiation exposure. There is some evidence that iodine may play a role in the prevention of aggressive thyroid cancer. It can also cut the risk of exposure to radiation from nuclear accidents if it is given in advance of the exposure.
What should I do if I’m concerned about my risk for thyroid cancer?