Clinicopathologic predictors of incidental thyroid cancer in Graves' disease: a single-center retrospective cohort study.

The necessity of total thyroidectomy for Graves' disease (GD) remains a subject of debate due to lifelong thyroxine replacement therapy. However, total thyroidectomy is a definitive treatment and allows for the detection of incidental thyroid cancer (ITC), which may necessitate further surgical intervention if not initially treated. This study aimed to investigate the prevalence, clinicopathological characteristics, and risk factors associated with ITC in GD patients undergoing total thyroidectomy. We conducted a retrospective cohort study of 86 GD patients who underwent total thyroidectomy from January 2016 to December 2022. Clinical and pathological characteristics were analyzed to determine potential risk factors associated with ITC. The incidence of ITC was 15.1% (13/86), predominantly papillary thyroid microcarcinoma (PTMC) at 9.3% (8/86). Patients with ITC were significantly older (mean age 45.2 years vs. 36 years, p = 0.017) and more frequently presented thyroid nodules on ultrasound (84.6% vs. 45.2%, p = 0.014). Multivariate analysis identified thyroid volume as a significant protective factor, with each 1 mL increase reducing ITC risk by approximately 6% (p = 0.009). Older age, smaller thyroid volume, and the presence of thyroid nodules on ultrasound were significantly associated with increased ITC risk. A larger thyroid volume may be associated with a lower risk of ITC. Careful preoperative evaluation, including assessment of thyroid nodules on ultrasound, is advised in older patients and those with smaller glands. Surgical decisions should be guided by individual risk factors and shared decision-making.