Peripheral thyrotropin receptor mRNA as a novel marker for differentiated thyroid cancer diagnosis and surveillance

Thyroid cancer is the most prevalent endocrine cancer whose incidence rates, particularly among women, have increased over the last decade. Although survival outcomes following surgery (with or without radioactive iodine ablation treatment) remain favorable, a significant proportion of patients are at lifetime risk of locoregional lymph node recurrence and distant metastasis. Serum thyroglobulin (Tg) has been the only circulating marker in routine use for detecting thyroid cancer recurrence, but it lacks sensitivity and is unreliable when Tg antibodies are present. New molecular markers for thyroid cancer have been investigated, with most based on detection in thyroid nodule or tumor tissue specimens. Recently, it has become possible to detect thyroid cancer cells in peripheral blood by measuring the mRNA of thyroid-specific genes, such as the mRNA of Tg and thyrotropin receptor. These have become promising new circulating markers for thyroid cancer. This review highlights the progress in this field from the perspective of improved initial cancer diagnosis and enhanced ability to monitor thyroid cancer recurrence.