Thyroglobulin and thyroid cancer

Thyroglobulin (Tg), the substrate of thyroid hormone production, is a tumor marker used in the surveillance of differentiated thyroid cancer. Measurement by immunoassay has become increasingly sensitive, providing a window into the presence of residual and recurrent disease. However, testing is plagued by the challenge of Tg autoantibodies present in a substantial portion of the cancer population. Assays utilizing liquid chromatography-tandem mass spectrometry circumvent this problem but are not free from potential hurdles. Here, we review the current clinical application of Tg measurement, the challenge posed by anti-Tg antibodies to standard immunometric platforms, and the development of mass spectrometry-based approaches. Efforts to harmonize (or assess harmonization) of newer methods and further improve sensitivity are discussed, as well as clinical workflows for using mass spectrometry alongside standard immunoassay testing.