Survivors of childhood cancer are 18 times more likely to develop thyroid cancer than the general population, according to the results of a study published in the International Journal of Cancer.
Survivors of childhood cancers are often at risk for long-term and late effects of cancer and its treatment. This includes the development of second cancers later in life, often as a result of exposure to radiation therapy. The British Childhood Cancer Survivor Study (BCCSS) was designed to monitor the late effects of treatment in childhood cancer survivors and includes 17,980 survivors of childhood cancer who had been diagnosed between 1940-1991 and had survived at least five years.
After a median follow-up of 17.4 years per survivor, the researchers identified 50 cases of thyroid cancer compared with an estimated 2.8 cases for the general population. Eighty-eight percent of patients who developed thyroid cancer had received radiation therapy near the thyroid gland. Survivors of Hodgkin’s disease and non-Hodgkin’s lymphoma appeared to be at the greatest risk of developing thyroid cancer. Survivors who had been treated with radiation were more than four times as likely to develop thyroid cancer compared with those who were not treated with radiation.
The researchers concluded that childhood cancer survivors are at a high risk of developing thyroid cancer, especially if they receive radiation in or around the thyroid area.
 Taylor AJ, Croft AP, Palace AM, et al. Risk of thyroid cancer in survivors of childhood cancer: Results from the British Childhood Cancer Survivor Study. International Journal of Cancer. 2009; 125: 2400-2405.