LAUSR

Radioactive iodine (RAI) is widely used to treat patients with Graves’ disease, as either initial therapy or following failure of thionamides, and thyroid nodular autonomy. The recent publication of a study fromKitahara and colleagues [1], indicating a slightly higher relative risk of breast cancer in hyperthyroid patients receiving RAI therapy, started a large debate that is mainly focused on methodological limitations [2–4]. Quite surprisingly, two of Kitahara’s study co-authors showed, using data from the same cohort, that the standardizedmortality ratio (SMR) for breast cancer is higher for patients treated with antithyroid drugs compared with patients treated with RAI [5]. Finally, Gronich and colleagues recently investigated the association of RAI treatment with the development of cancers (both all and site-specific) in 16,637 hyperthyroid patients treated with RAI or thionamides [6]. Overall, 825 newly diagnosed cancers were detected during follow-up, and, as the main result, RAI was not associated with a higher risk of any cancer, breast cancer, colorectal cancer, prostate cancer, stomach cancer, or urinary tract cancer, compared with thionamides. Additionally, RAI therapy was associated with a lower risk of thyroid cancer, while treatment with thionamides was associated with a higher overall mortality rate than treatment with RAI. Surprisingly, while Kitahara’s saga was raging, relevant concerns raised about the association of hyperthyroidismwith cardiovascular mortality and risk of dementia went almost unnoticed as well as the inclusion of acute pancreatitis as a serious side effect of methimazole.