Endocrine Abstracts

Background: Current therapeutic options for Graves’ disease (GD) include antithyroid drugs (ATD), radioactive iodine (RAI) or thyroidectomy. ATD treatment is widely used but the relatively high recurrence rate (~50%) after ATD discontinuation is a major concern. Identification of risk factors predicting relapse in GD patients after stopping ATD is decisive to guide initial treatment choices.

Methods: We conducted a retrospective study to determine the recurrence risk and investigate predictors for relapse in GD patients after a treatment course of ATD. Consecutive patients with Graves’ hyperthyroidism who attended our endocrine service since 2004 were identified and medical records analysed. Remission was defined as maintaining a euthyroid status for at least one year after ATD withdrawal.

Results: 262 patients with GD were identified. 249 patients opted for initial ATD therapy with intention to treat but 219 (88%) completed ATD treatment as per protocol (75% female, age at diagnosis 44.5±14.6 years). On initial evaluation, 36% (64/180) were active smokers, 65% (136/209) had a palpable goitre and 28% (53/192) had Graves’ orbitopathy. At one year after ATD withdrawal, 142 patients (65%) were in remission. During 7.1 years (range 1.5–17.0 years) median follow-up, four patients continued medical therapy and 85 patients (40%) achieved long-term remission after completing first ATD course. Smoking (RR 1.39, CI 1.06–1.82) and large goitre size (RR 1.60, CI 1.20–2.13) were significant independent predictors for disease recurrence after first treatment course. Age at diagnosis, gender, orbitopathy and initial serum free T4 level showed no significant association with relapse in ATD-treated patients.

Conclusion: In our cohort, smoking and goitre size were significant pretreatment risk factors for disease relapse following an initial course of ATD. These factors must be duly considered at the time of initial assessment to facilitate an informed decision on the most appropriate therapeutic approach for individual patients.