ETA2023 Poster Presentations Graves’ Disease (9 abstracts)
1Korea University College of Medicine, Internal Medicine, Seoul, Korea, Rep. of South; 2Korea University Colleg of Medicine, Department of Surgery, Seoul, Korea, Rep. of South; 3Korea University Colleg of Medicine, Internal Medicine, Seoul, Korea, Rep. of South; 4Korea University Colleg of Medicine, Department of Otorhinolaryngology-Head and Neck Surgery, Seoul, Korea, Rep. of South
Objectives: Radioactive iodine (RAI) therapy has potential therapeutic effects in treating Graves disease (GD). However, whether RAI therapy for GD can increase cancer risk remains a controversial issue in medicine and public health.
Methods: Using the Korean National Health Insurance Service-National Health Information Database (NHIS-NHID, 20022020), we investigated hazard ratios (HRs) of overall and site-specific cancer associated with RAI in GD. Subsequent cancer was only defined as a primary malignancy treated at least 1 year after RAI therapy.
Results: A total of 10,737 GD patients who received RAI therapy (7,193 women, 67.0%; mean age, 43.7 ± 13.4 years) were matched to 53,003 GD patients without RAI therapy (35,471 women, 66.9%; mean age 43.8 ± 13.2 years) in a 1:4~5 ratio by age, sex, and health check-up data. The median follow-up duration was 8.7 years (interquartile range [IQR]: 5.212.1), and the median cumulative RAI dose was 15.0 mCi (IQR 10.017.1) in the RAI therapy group. During 2004-2020, the overall subsequent cancer rates were 5.66 and 5.84 per 1,000 person-years in the RAI and non-RAI groups, respectively, with an unadjusted HR of 0.97 (95% CI, 0.881.06); this remained at 0.92 (95% CI, 0.811.04) after adjustment for multiple clinical confounding factors. For leukemia, incidence rates were 0.12 and 0.05 per 1,000 person-years in the RAI and non-RAI groups, respectively, with an unadjusted HR of 2.39 (95% CI, 0.174.91): however, HR was insignificant of 2.03 (95% CI, 0.735.60) after adjustment for confounding factors.
Conclusions: This study identified that the overall cancer risk in GD patients with RAI therapy compared to those without was not significant in Korea. Further long-term studies are needed on the risks and advantages of RAI therapy in patients with GD.