Cancer risk in patients with Graves' disease: a nationwide cohort study

The possibility of an association of Graves' disease (GD) with subsequent cancers has been previously reported.

Our study used the Taiwanese National Health Insurance Research Database (NHIRD), which identified 5025 newly diagnosed GD patients from 1997 to 2010, and 20,100 frequency matched non-GD patients. The risk of developing cancer for GD patients was measured using the Cox proportional hazard model.

The incidence of developing cancer in the GD cohort was 4.92 per 1000 person-years and was 1.37-fold higher than in the comparison cohort (p<0.001). Compared with patients aged 20-34 years, older age groups demonstrated a higher risk of developing cancer (35-49 years: hazard ratio (HR)=4.15; 50-64 years: HR=7.39;≥65 years: HR=13.4). After adjusting for sex, age, and comorbidities, the HR for developing breast cancer and thyroid cancer was 1.58- and 10.4-fold higher for patients with GD. Furthermore, the incidence rates (IRR) were the highest in the first three years: 2.06 [confidence interval (CI)=1.87-2.27] and 15.6 [CI=13.9-17.5] in breast cancer and thyroid cancer with GD respectively. Specifically, a 16-fold hazard of developing thyroid cancer was present in the first three years in the GD cohort compared to the non-GD cohort [CI=7.95-32.1].

GD patients have a higher risk of cancer, particularly thyroid and breast cancer sequent within six and three years respectively. Strategies for preventing thyroid and breast cancer are proposed.