Does RAIT contribute to thyroid cancer development?

Treatment with radioiodine therapy (RAIT) for Graves’ disease (GD) does not seem to increase the incidence of new thyroid cancer cases, reports a study.

A retrospective analysis was conducted in a total of 13,874 eligible patients diagnosed with untreated GD. The person-year method was then used to evaluate the incidence rates of newly developed thyroid cancer by each treatment method for GD.

The authors analysed patients who developed thyroid cancer following RAIT among those who underwent the procedure for GD, including participants with recurrent GD or a history of prior treatment for GD. They also performed logistic regression analysis to examine the risk factors for thyroid cancer.

Of the patients, 2,273 underwent RAIT, 287 had surgical treatment, and 11,314 received medication only. New-onset thyroid cancer was identified in eight patients in the RAIT group and 39 in the medication-only group.

No significant difference was noted in the incidence rate of thyroid cancer with treatment for GD over 107,218 person-years observed.

Of the patients who underwent RAIT, 17 developed thyroid cancer. Sixteen had a diagnosis of papillary thyroid carcinoma (PTC), of which 15 were microcarcinomas. No significant risk factors were found for thyroid cancer development in logistic regression analysis.

“Most thyroid cancers that developed after RAIT were micro-PTCs, with no evidence suggesting a poor prognosis,” the authors said.