IRP study finds long-term increased risk of cancer death following common treatment for hyperthyroidism

Monday, July 1, 2019

Findings from a study of patients who received radioactive iodine (RAI) treatment for hyperthyroidism show an association between the dose of treatment and long-term risk of death from solid cancers, including breast cancer. The study, led by researchers at the National Cancer Institute (NCI), part of the National Institutes of Health, was published July 1, 2019 in JAMA Internal Medicine.

“We identified a clear dose–response relationship between this widely used treatment and long-term risk of death from solid cancer, including breast cancer, in the largest cohort study to date of patients treated for hyperthyroidism,” said Cari Kitahara, Ph.D., of NCI’s Division of Cancer Epidemiology and Genetics, lead author of the study . “We estimated that for every 1,000 patients treated currently using a standard range of doses, about 20 to 30 additional solid cancer deaths would occur as a result of the radiation exposure.”

RAI, which has been used widely in the United States for the treatment of hyperthyroidism since the 1940s, is one of three commonly used treatments for hyperthyroidism. The other two are anti-thyroid drugs, which have been rising in popularity, and surgical treatment, which is used least often.