Thyroid cancer linked to radiation exposure, more studies confirm

Sunday April 26, 2009 (foodconsumer.org) -- Radiation exposure at an early age has long been established as a catalyst for thyroid cancer later in life. At Toronto's Mt. Sinai Hospital, 125 patients who underwent thyroid surgery as a result of both cancerous and benign tumors were analyzed extensively to further link radiation to the formation of those tumors. All patients had been exposed to radiation at least 3 years prior to their diagnosis.

The April issue of JAMA's Archive of Otolaryngology reports that in comparison to a group of patients who had not been exposed to radiation, the study group was more likely to have a more aggressive form of the disease, due to radiation induced changes in tissue.

Fifty-six percent of the patients had direct exposure to radiation through other medical procedures; others, such as x-ray technicians, were in contact with radiation on a daily basis. According to the New York Times, a common diagnostic practice in the 1950s was to use radiation to treat enlarged adenoids and tonsils, as well as certain skin conditions.

Researchers began to notice the correlation between cancer and radiation as early as 1960, when they determined that those more likely to contract the disease had been exposed to some form of radioactive treatment at five years of age or younger. It was then determined that 80% of those who developed tumors by their late teens and early twenties had been exposed to radiation as a result of these treatments.

The Mt. Sinai study outcomes were in line with research findings after studying atomic bomb survivors, and those who were children at the time of the Chernobyl incident. Studies of cancer occurrence among those living within a certain radius of the Nevada test site further confirm these statistics, according to the New York Times.

The Toronto study followed patients for 10 years, and found that the radiation group was more likely to have had a recurrence of cancer or metastases in other parts of the body. Additionally, they were more likely to have required a complete removal of the thyroid gland as a result of the cancer.

The Toronto study simply verified earlier studies: those who are exposed to radiation, especially at an early age, are more susceptible to an uncompromising form of thyroid cancer that could recur or metastasize over time.

(By Rachel Stockton, and edited by Heather Kelley)