Society for Endocrinology - a world-leading authority on hormones

12 Dec 2019

Joint Society statement issued on cancer risk & hyperthyroidism

Society for Endocrinology and British Thyroid Association statement advises caution on interpretation of “Association of Radioactive Iodine Treatment With Cancer Mortality in Patients With Hyperthyroidism” 

Caution is advised in interpreting the findings of the recent JAMA Internal Medicine publication1 on radioactive iodine treatment for hyperthyroid patients and cancer mortality. The paper’s conclusion that “in RAI-treated patients with hyperthyroidism, greater organabsorbed doses appeared to be modestly positively associated with risk of death from solid cancer, including breast cancer”, has raised concerns among patients and clinicians.

To help address the concerns of patients and clinicians, the Society for Endocrinology and British Thyroid Association have issued a statement2 indicating that caution is needed in interpreting these findings. Although this retrospective analysis of data from the large multicentre Cooperative Thyrotoxicosis Therapy Follow‐up study does suggest a modest increase in potential risk of death from cancer in people who receive radioiodine therapy for hyperthyroidism, there are some limitations to take into account. Our statement highlights these caveats and advises that more research is needed.

“Radioiodine is a very effective treatment for hyperthyroidism and has been used successfully for more than 70 years. The recent JAMA Internal Medicine article has raised concerns for health care practitioners and patients. We felt that the findings of this paper need to be interpreted in the right context and that continued surveillance of patients who have been treated with radioiodine is required.” The Society for Endocrinology Clinical Committee & the British Thyroid Association Executive Committee

Read the full statement published as a Clinical Endocrinology preprint.



1 Association of Radioactive Iodine Treatment With Cancer Mortality in Patients With Hyperthyroidism,  Cari M. Kitahara, PhD1; Amy Berrington de Gonzalez, DPhil1; Andre Bouville, PhD (Retired)1; et al.,

JAMA Intern Med. 2019;179(8):1034-1042. doi:10.1001/jamainternmed.2019.0981

2 Joint Statement from the Society for Endocrinology and the British Thyroid Association regarding “Association of Radioactive Iodine Treatment With Cancer Mortality in Patients With Hyperthyroidism” Peter N Taylor, Onyebuchi E Okosieme, Krishna Chatterjee, Kristien Boelaert, The Executive Committees of the Society for Endocrinology and The British Thyroid Association

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The Society for Endocrinology is a UK-based membership organisation representing a global community of scientists, clinicians and nurses who work with hormones. Together we aim to improve public health by advancing endocrine education and research, and engaging wider audiences with the science of hormones.

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