Which marker is used postoperatively to monitor thyroid cancer?

Which marker is used postoperatively to monitor thyroid cancer?

• A. Thyroglobulin
• B. Calcitonin
• C. CEA
• D. TSH

Answer: (A)

Thyroglobulin is used as a postoperative marker for differentiated thyroid cancer because it is produced by thyroid tissue, including most differentiated cancers. After complete thyroid removal and radioactive iodine ablation, normal thyroid tissue is minimized, so thyroglobulin should be very low or undetectable. If thyroglobulin appears in follow-up testing, it signals residual thyroid tissue or metastases, guiding further imaging and management. To maximize sensitivity, thyroglobulin is measured with TSH stimulation (either by withdrawing thyroid hormone to raise TSH or by giving recombinant TSH). Be aware that anti-thyroglobulin antibodies can interfere with Tg measurements, so their presence necessitates alternative assessment or monitoring of antibody trends. Calcitonin is a marker for medullary thyroid carcinoma, not routine monitoring for differentiated thyroid cancer; CEA is non-specific, and TSH is a regulatory hormone, not a tumor marker.

Thyroglobulin is used as a postoperative marker for differentiated thyroid cancer because it is produced by thyroid tissue, including most differentiated cancers. After complete thyroid removal and radioactive iodine ablation, normal thyroid tissue is minimized, so thyroglobulin should be very low or undetectable. If thyroglobulin appears in follow-up testing, it signals residual thyroid tissue or metastases, guiding further imaging and management. To maximize sensitivity, thyroglobulin is measured with TSH stimulation (either by withdrawing thyroid hormone to raise TSH or by giving recombinant TSH). Be aware that anti-thyroglobulin antibodies can interfere with Tg measurements, so their presence necessitates alternative assessment or monitoring of antibody trends. Calcitonin is a marker for medullary thyroid carcinoma, not routine monitoring for differentiated thyroid cancer; CEA is non-specific, and TSH is a regulatory hormone, not a tumor marker.