The incidence of many cancers is decreasing, but thyroid cancer is on the rise. Popular television host Dr. Oz this week suggested the increase could be linked to excessive use of dental X-rays and mammograms.
Risk factors for thyroid cancer include hereditary conditions and iodine deficiency, though the latter is rare in the United States because of iodized salts. Thyroid cancer is also four times more likely to occur in women than men, leading some to suggest that estrogen might fuel the growth of thyroid cancer. (Estrogen is also linked to some types of breast cancer.)
Another leading risk factor for thyroid cancer scientists have identified is radiation exposure.
The thyroid gland is very sensitive to radiation, Dr. Oz explains. Even though routine dental X-rays, chest X-rays and mammograms use lower amounts of radiation than in years past, it still may pose a problem because they are used more frequently than ever before.
But there are ways we can help protect our thyroid gland from X-ray exposure. Often, when X-rays are preformed, the technician places a lead apron over the body to protect it from unwanted rays. Many of these aprons have thyroid shields that can be folded up to cover the thyroid, though they are not always used. Separate lead thyroid shields are also available and should be on hand at offices that perform mammograms. Most women have to ask for them, however.
Doctors say that the advice is good, and that it is always best to play it safe. However, there is no cause for alarm.
“We’ve said for years that the amount of radiation from dental X-rays is not enough to cause cancer,” Dr. Leonard Wartofsky, a thyroid cancer specialist at Washington Hospital in the District of Columbia said to the New York Times. And, “the doses associated with mammography have been studied and well calibrated. As long as it is done with modern equipment, women should not be concerned. That degree of radiation is not consequential.”