Incidence of Primary Brain and Other Solid Tumors Following Low and High Dose Radioactive Iodine Therapy in Hyperthyroidism and Thyroid Cancer. Is It Coincidence or Is There a Real Association?

Saturday, April 13, 2024

10:00 AM - 10:00 PM ET

Location: Foyer Kiosk

First Author(s)

JT

John Hollis Tackett, BS

Student
University of Mississippi Medical Center
University of Mississippi Medical Center
Flowood, Mississippi, United States

Co-Author(s)

JY

Johnny Yang, BS, BA

Medical Student
University of Mississippi Medical Center
University of Mississippi Medical Center, United States
ML

Marjorie Lam, BA

Medical Student
University of Mississippi Medical Center, United States
ES

Easton Sheffield, BS

Medical Student
University of Mississippi Medical Center
University of Mississippi Medical Center
Flowood, Mississippi, United States
CC

Chanukya Cherukuri, BS

Medical Student
University of Mississippi Medical Center
University of Mississippi Medical Center, United States
BB

Bryson Brister, BS

Medical Student
University of Mississippi Medical Center
University of Mississippi Medical Center
Brandon, Mississippi, United States
JS

John D. Salvemini, MS

Medical Student
University of Mississippi Medical Center
University of Mississippi Medical Center, United States
VV

Vani Vijayakumar, MD

Professor
University of Mississippi Medical Center, United States

Purpose: To review the literature on if RAI therapy for patients with hyperthyroidism or thyroid cancer is associated with the development of subsequent primary brain tumors or other solid tumors with a few of our own examples.

Methods/Materials: Using MEDLINE, PubMed, and Google Scholar, a literature review was conducted to assess the findings of studies that investigated possible associations between RAI therapy and subsequent tumor development in patients with hyperthyroidism and thyroid cancer. Key words used in the search included “radioactive iodine treatment,” “cancer risk,” “cancer mortality,” “hyperthyroidism,” and “DTC.” Commentaries, editorials, and unpublished works were excluded. Cases from a tertiary academic center were also reviewed to compare with current literature.

Results: For patients with hyperthyroidism, the overall cancer risk after receiving RAI therapy was insignificant, but a linear dose-response positive association between RAI exposure and solid-cancer mortality was observed and was particularly high for breast cancer.

Thyroid cancer patients treated with RAI showed a slightly elevated risk for developing subsequent malignancies. Hematological malignancies showed a significant association but a low absolute case number due to low incidence among survivors. Neurologic malignancies showed an uncertain association. No difference was found between tumor features and mortality risks in the general population.

Cases from a tertiary academic center showed similar results to the reviewed studies, with two patients treated with RAI later developing brain tumors years after treatment that were most likely not related to their treatment.

Conclusions: RAI therapy, especially when given in higher doses, may warrant caution in patients with hyperthyroidism due to an increased risk of solid-cancer mortality and may cause hematologic malignancies in thyroid patients in rare cases. Further studies in both patient populations focusing on eliminating biases and confounders might help produce more definitive associations.