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

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.