Thyroglobulin (Tg) is a widely used biomarker of various differentiated thyroid cancer (DTC); Tg is a substrate for thyroid hormone production. Detection and quantification of serum thyroglobulin levels remain challenging due to Tg’s size, heterogeneity, and thyroglobulin autoantibodies (TgAb). Immunoassays offer the opportunity to tailor DTC treatments, but many patients are TgAb positive, excluding them from analysis during regression.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can overcome immunoassay issues by digestion of Tg to a tryptic peptide removing the interference from TgAbs.