Cancer and Mortality Risks of Graves’ Disease in South Korea Based on National Data from 2010 to 2019

Purpose: This study aimed to investigate Graves’ disease (GD) associated cancer and mortality risk using a Korean population-based study. Patients and Methods: We included 6435 patients with GD using the Korean National Health Insurance Service–National Sample Cohort database from 2010 to 2019. Data concerning such patients were compared in a 1:5 ratio with age-and sex-matched non-GD group (n=32,175). Eighteen subdivided types of cancer and cancers-in-total were analyzed. In addition to the mortality analysis, subgroup analyses were performed according to age and sex. Results: After adjustment, the hazard ratio (HR) of the GD group for cancer-in-total was 1.07 (95% confidence interval [CI], 0.91– 1.27), showing no difference when compared to the non-GD group. However, among different types of cancer, the thyroid cancer risk of the GD group was higher than that of the non-GD group (HR=1.70; 95% CI, 1.20–2.39). When subdivided by age and sex, the thyroid cancer risk of the GD group in males aged 20–39 years was higher than that of the non-GD group (HR=7.00; 95% CI, 1.48– 33.12). The mortality risk of the GD group was not different from that of the non-GD group (HR=0.86; 95% CI, 0.70–1.05). Conclusion: In South Korea, patients with GD had a higher risk of thyroid cancer than the non-GD group. In particular, males aged 20–39 years with GD were more likely to have thyroid cancer than the non-GD group.