# Thyroglobulin Autoantibodies Do Not Influence the Outcome of Patients With Differentiated Thyroid Carcinoma

## TL;DR

Thyroglobulin autoantibodies are common in thyroid cancer patients but do not affect survival, though they can interfere with monitoring.

## Contribution

This study clarifies that thyroglobulin autoantibodies do not influence clinical outcomes in differentiated thyroid carcinoma patients.

## Key findings

- TgAb presence does not impact overall or disease-free survival in DTC patients.
- TgAb-positive patients require close monitoring due to unreliable thyroglobulin measurements.

## Abstract

Thyroglobulin (Tg) is a sensitive and specific marker for differentiated thyroid carcinoma (DTC). The presence of thyroglobulin autoantibodies (TgAb) can interfere with Tg measurement in commonly used immunoassays, often resulting in falsely low or undetectable Tg levels. However, data on the prognostic significance of TgAb or its potential utility as a surrogate marker for DTC are limited, leaving its role in the clinical management of DTC uncertain. The aim of this study was the evaluation of the prognostic significance of TgAb in a clinical cohort of patients with DTC.

We included n = 289 patients with DTC who presented to our clinic for radioiodine treatment. Clinical data and follow‐up outcomes were retrospectively analysed. The TgAb status at initial treatment and during follow‐up was assessed, and its association with disease remission, persistence or recurrence was evaluated.

Roughly 25% of DTC patients in our cohort showed positive TgAb post‐surgery. There were no significant differences between TgAb‐positive and TgAb‐negative patients in histology, tumour size, metastasis, therapeutic regimen or risk stratification.

The presence of TgAb did not influence the outcome regarding overall and disease‐free survival. Results implicate that the initial appearance of TgAb does not influence the outcome of patients with DTC. Patients with positive TgAb should be monitored closely during follow‐up as Tg measurement is unreliable, while overtreatment should be avoided.

Thyroglobulin autoantibodies (TgAb) occur in roughly 25% of thyroid cancer patients and interfere with Tg measurement. Our study shows TgAb presence does not affect patient outcomes, but close monitoring is essential to avoid overtreatment.