Is thyroglobulin a reliable biomarker of differentiated thyroid cancer in patients treated by lobectomy? A systematic review and meta-analysis.

OBJECTIVES: The prognostic role of thyroglobulin in predicting recurrence in differentiated thyroid cancer (DTC) patients treated by lobectomy is controversial. This systematic review with meta-analysis aimed to update the current evidence deepening the reliability of circulating thyroglobulin in assessing the early response and in predictive recurrence. METHODS: The methodology was registered in the PROSPERO database under the protocol number CRD42021288189. A systematic search was carried out on PubMed, Embase, Web of Science, and Scopus from September to November 2021 without time and language restrictions. The literature search strategy was based on the following keywords: Thyroglobulin AND (Lobectomy OR Hemithyroidectomy). RESULTS: After screening 273 articles, seven studies were included in the systematic review, and only six of them were included in the meta-analysis for a total of 2,455 patients. Circulating thyroglobulin was found non-reliable in assessing early response and predicting recurrence in patients with hemithyroidectomy, especially those with a low initial ATA classification. CONCLUSIONS: Our study does not support serum thyroglobulin levels for monitoring patients with low-risk DTC treated with lobectomy, and weak evidence supports its role for intermediate- or high-risk patients. Studies with longer follow-up, different study designs, and stringent inclusion/exclusion criteria are needed to evaluate the role of thyroglobulin in recurrence prediction.