Prevalence of Papillary Thyroid Carcinoma is Significantly Higher in Graves Disease with Synchronous Thyroid Nodules

The association between autoimmunity-related tissue injury and thyroid cancer development remains an area of interest. Evidence suggests that patients with Graves disease (GD) may have an elevated risk for differentiated thyroid cancer. Multicenter studies are needed to gain insight into the correlates of papillary thyroid carcinoma (PTC) identified in this particular group of patients. This study aimed to investigate the prevalence of PTC and synchronous thyroid nodules in thyroidectomy specimens from GD patients in an endemic goiter region.

A retrospective review of institutional pathology records at two tertiary care centers identified 237 surgically treated patients with GD. Patients were categorized as having nodular Graves disease (N-GD) if synchronous nodular thyroid was identified by ultrasonography, while those without synchronous thyroid nodules were categorized as non-nodular or simple Graves disease (S-GD). The prevalence of PTC, histopathological correlates, and demographic characteristics were recorded and compared between groups N-GD and S-GD.

One hundred thirty-one and 106 patients were assigned to N-GD and S-GD, respectively. The mean age was significantly higher in N-GD (mean 45.52 years) compared to S-GD (mean 35.18 years) (p < 0.001). The overall frequency of PTC was 36.3% (86/237) in the entire cohort. PTC was identified in 48.1% (63/131) of N-GD and 21.7% (23/106) of S-GD (p < 0.001). Subcentimeter tumors constituted the majority of cases in both groups (76.2% in N-GD and 82.6% in S-GD) (p > 0.05). The group of S-GD was enriched in BRAF-like PTCs, whereas N-GD had equal distribution for RAS- and BRAF-like tumors.

This study underscores that the majority of PTCs encountered in GD were enriched in low-risk subcentimeter PTCs with a prevalence that varies depending on the presence of underlying nodular thyroid tissue.