Thyroid-stimulating immunoglobulin is not associated with aggressive clinicopathologic features in concomitant Graves' disease and papillary thyroid cancer.

Overview

BACKGROUND: Graves' disease has been associated with increased tumor aggressiveness in differentiated thyroid carcinoma, however, its correlation with thyroid stimulating immunoglobulin (TSI) remains unclear. METHODS: A tri-institutional retrospective review of 96 thyroidectomy patients with Graves' disease and papillary thyroid carcinoma (PTC) was performed (2002-2020). Clinicopathologic features and recurrence were compared based on TSI level. RESULTS: ATA risk stratification distribution was low (72.9 %), intermediate (14.6 %), and high (12.5 %). Recurrence rate was 11.5 % with median follow-up of 3.2 years. TSI was not associated with high-risk clinicopathologic features at its 50 % and 75 % quartiles. There was no difference in median TSI between patients with recurrence versus no recurrence [212 (IQR 98-361) vs. 327 (IQR 152-461), p = 0.148]. TSI was not associated with recurrence on univariable Cox regression, even when excluding microcarcinomas. CONCLUSIONS: In this majority low-risk PTC cohort with concomitant Graves' disease, TSI level is not associated with aggressive clinicopathologic features or recurrence.