{"entity":{"id":"thyroid-cancer-markers","kind":"technology","name":"Thyroglobulin, calcitonin and CEA in thyroid cancer follow-up","aka":["thyroglobulin","calcitonin","calcitonin doubling time","thyroglobulin antibodies","thyroid cancer blood tests"],"tldr":"After the thyroid is removed for cancer, a blood protein it alone makes, thyroglobulin, should fall to nothing, so any measurable level in follow-up means cancer is still there; in medullary thyroid cancer the same job is done by calcitonin and CEA, whose doubling time forecasts how fast the disease will move.","summary":"What they measure. Thyroglobulin is the storage protein for thyroid hormone and is made only by thyroid follicular cells, normal or cancerous. After total thyroidectomy and radioactive iodine for papillary or follicular thyroid cancer, it should become undetectable; a measurable or rising level means residual or recurrent disease. Modern high-sensitivity assays make the old practice of stopping thyroid hormone to stimulate thyroglobulin unnecessary for most patients. Anti-thyroglobulin antibodies, present in about a quarter of patients, interfere with the assay and must be measured alongside it; a falling antibody titre is itself reassuring. Medullary thyroid cancer arises from C cells, which make calcitonin and often carcinoembryonic antigen (CEA); both are measured before surgery, at three to six months after, and then according to the result.\n\nWhat changes. The American Thyroid Association guidelines set the response categories for differentiated thyroid cancer (excellent, indeterminate, biochemical incomplete, structural incomplete) largely from thyroglobulin, antibodies and neck ultrasound, and the category decides how intensive follow-up and thyroid hormone suppression should be; an excellent response allows follow-up to be relaxed to yearly and suppression to be eased. In medullary thyroid cancer, an undetectable post-operative calcitonin means cure in most cases; a raised level triggers imaging, and the doubling time of calcitonin and CEA (under six months is ominous, over two years reassuring) is the strongest predictor of survival and the usual trigger for starting a RET or multikinase inhibitor.\n\nCaveats and cost. Thyroglobulin is uninformative before the thyroid is removed and in patients with remaining normal thyroid tissue; assays differ, so serial values should come from one laboratory. Calcitonin is also raised by kidney failure, proton pump inhibitors and other neuroendocrine tumours. Both tests cost a few pounds and are available in any hospital laboratory, and they are the reason most thyroid cancer follow-up needs no scans.","status":"standard-of-care","asOf":"2026-09-17","links":[{"label":"2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer (Thyroid 2016)","url":"https://doi.org/10.1089/thy.2015.0020"},{"label":"Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma (Thyroid 2015)","url":"https://doi.org/10.1089/thy.2014.0335"}],"tags":[],"related":[],"cancers":["thyroid","papillary-thyroid-cancer","follicular-thyroid-cancer","medullary-thyroid-cancer","multiple-endocrine-neoplasia"],"sections":["diagnostics"],"technologies":["serum-tumour-markers","germ-cell-tumour-markers","cea-surveillance-colorectal","thyroid-fna-molecular","ultrasound","hand-held-ultrasound"],"targets":["ret","ceacam5"],"drugs":["selpercatinib","vandetanib","cabozantinib"],"companies":[],"institutions":[],"pathways":[],"terms":["tumour-marker","tumour-markers","thyroidectomy","radioactive-iodine"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"principle":"Serum thyroglobulin with anti-thyroglobulin antibodies after total thyroidectomy tracks differentiated thyroid cancer; serum calcitonin and CEA with doubling-time calculation track medullary thyroid cancer, per American Thyroid Association response categories.","strengths":["Tissue-specific, so a measurable level after surgery is meaningful","Doubling time forecasts medullary thyroid cancer behaviour","Cheap and replaces routine imaging in most follow-up"],"limitations":["Thyroglobulin antibodies interfere in a quarter of patients","Uninformative when normal thyroid tissue remains","Assay differences across laboratories"]},"route":"/technologies/thyroid-cancer-markers/","neighbours":{"cancer":[{"id":"follicular-thyroid-cancer","kind":"cancer","name":"Follicular thyroid cancer","route":"/cancers/follicular-thyroid-cancer/"},{"id":"medullary-thyroid-cancer","kind":"cancer","name":"Medullary thyroid cancer","route":"/cancers/medullary-thyroid-cancer/"},{"id":"multiple-endocrine-neoplasia","kind":"cancer","name":"Multiple endocrine neoplasia syndromes (MEN1, MEN2, MEN4)","route":"/cancers/multiple-endocrine-neoplasia/"},{"id":"papillary-thyroid-cancer","kind":"cancer","name":"Papillary thyroid cancer","route":"/cancers/papillary-thyroid-cancer/"},{"id":"thyroid","kind":"cancer","name":"Thyroid cancer","route":"/cancers/thyroid/"}],"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"}],"technology":[{"id":"germ-cell-tumour-markers","kind":"technology","name":"AFP, hCG and LDH in germ cell tumours (IGCCCG risk groups)","route":"/technologies/germ-cell-tumour-markers/"},{"id":"cea-surveillance-colorectal","kind":"technology","name":"CEA surveillance after colorectal cancer surgery","route":"/technologies/cea-surveillance-colorectal/"},{"id":"hand-held-ultrasound","kind":"technology","name":"Hand-held and point-of-care ultrasound","route":"/technologies/hand-held-ultrasound/"},{"id":"serum-tumour-markers","kind":"technology","name":"Serum tumour markers: proper use and misuse","route":"/technologies/serum-tumour-markers/"},{"id":"thyroid-fna-molecular","kind":"technology","name":"Thyroid nodule FNA, Bethesda cytology & molecular classifiers","route":"/technologies/thyroid-fna-molecular/"},{"id":"ultrasound","kind":"technology","name":"Ultrasound","route":"/technologies/ultrasound/"}],"target":[{"id":"ceacam5","kind":"target","name":"CEACAM5","route":"/targets/ceacam5/"},{"id":"ret","kind":"target","name":"RET","route":"/targets/ret/"}],"drug":[{"id":"cabozantinib","kind":"drug","name":"Cabozantinib","route":"/drugs/cabozantinib/"},{"id":"radioactive-iodine","kind":"drug","name":"Radioactive iodine (I-131)","route":"/drugs/radioactive-iodine/"},{"id":"selpercatinib","kind":"drug","name":"Selpercatinib","route":"/drugs/selpercatinib/"},{"id":"vandetanib","kind":"drug","name":"Vandetanib","route":"/drugs/vandetanib/"}],"term":[{"id":"thyroidectomy","kind":"term","name":"Thyroidectomy","route":"/terms/thyroidectomy/"},{"id":"tumour-marker","kind":"term","name":"Tumour marker","route":"/terms/tumour-marker/"},{"id":"tumour-markers","kind":"term","name":"Tumour markers (CEA, LDH, chromogranin, thyroglobulin)","route":"/terms/tumour-markers/"}]}}