Breast malignancy after radioactive iodine ablation for thyroid pathology: A systematic review of the literature.

Abstract

e22511 Background: Radioactive Iodine Ablation (RAI) is a procedure in which the administration of radioactive iodine is utilized to eradicate pathologic thyroid tissue. RAI is commonly used for thyroid malignancy and hyperthyroidism. Although RAI has been a mainstay of treatment for these diseases, there has been some controversy regarding the development of secondary primary malignancy after RAI. Breast cancer is a particular concern. As breast cancer is the second most common cancer for women in the United States, understanding its risk factors is a key component of public health. Methods: A systematic review was conducted following PRISMA guidelines. Inclusion criteria consisted of English language studies that evaluated the association between radioactive iodine ablation and secondary primary breast malignancy. The study was conducted from January 2023 until February 2023. Two independent researchers conducted the literature search utilizing PubMed, SCOPUS, JSTOR, and Wiley Library using standardized search terms. The titles and abstracts of these studies were independently screened, and further evaluated for relevancy. Qualitative data was then extracted and summarized. Results: Of the 386 manuscripts retrieved, 27 met inclusion criteria. These studies were published between 1983 – 2022. Of these, 15 articles reported no association between RAI and the development of secondary primary breast malignancy. Of the manuscripts which reported no association, 6 examined RAI for hyperthyroidism, and 9 examined RAI for thyroid malignancy. 12 studies reported an association between RAI and the development of secondary primary breast malignancy. Of the studies reporting an association, 1 examined RAI for hyperthyroidism, and the remaining 11 examined RAI for thyroid malignancy. For the single study that found an association in the case of hyperthyroidism, the researchers found a dose-dependent relationship. Conclusions: The literature surrounding secondary primary breast malignancy after RAI is controversial. This systematic review resulted in conflicting data regarding the association between radioactive iodine ablation for thyroid pathology and the development of secondary primary breast malignancy. The studies that suggested an association between RAI and secondary primary breast malignancy were overwhelmingly studies in which RAI was used for the treatment of thyroid malignancy. Some studies suggest a possible dose-dependent relationship between RAI and secondary primary breast malignancy, however this data is limited. Additional studies would be beneficial to address this gap in the literature.