Thyroid cancer in Graves' disease: is surgery the best treatment for Graves' disease?

Background Graves' disease is a common cause of thyrotoxicosis. Treatment options include anti-thyroid medications or definitive therapy: thyroidectomy or radioactive iodine (I-131). Traditionally, I-131 has been the preferred definitive treatment for Graves' disease in New Zealand. Reports of concomitant thyroid cancer occurring in up to 17% of Graves' patients suggest surgery, if performed with low morbidity, may be the preferred option. The aim of this study was to determine the rate of thyroid cancer and surgical outcomes in a New Zealand cohort of patients undergoing thyroidectomy for Graves' disease. Method This study is a retrospective review of Waikato region patients undergoing thyroid surgery for Graves' disease during the 10-year period prior to 1 December 2011. Results A total of 833 patients underwent thyroid surgery. Of these, 117 were for Graves' disease. Total thyroidectomy was performed in 82, near-total in 33 and subtotal in 2 patients. Recurrent thyrotoxicosis developed in one subtotal patient requiring I-131 therapy. There were two cases of permanent hypoparathyroidism and one of permanent recurrent laryngeal nerve palsy. Eight patients (6.8%) had thyroid cancer detected, none of whom had overt nodal disease. Five were papillary microcarcinomas (one of which was multifocal), two were papillary carcinomas (11 mm and 15 mm) and one was a minimally invasive follicular carcinoma. Conclusion Thyroid cancer was identified in approximately 7% of patients undergoing surgery for Graves' disease. A low complication rate (<2%) of permanent hypoparathyroidism and nerve injury (<1%) supports surgery being a safe alternative to I-131 especially for patients with young children, ophthalmopathy or compressive symptoms.