17. Diagnostic Molecular Markers in Thyroid Cancer

Thyroid cancer is the commonest classical endocrine tumor, accounting for approximately 1% of all cancers. The diagnosis of thyroid cancer is typically made on cytopathologic features on fine needle aspiration or histological features on surgical samples. Following treatment of patients with thyroidectomy, and in some cases radioiodine, patients are monitored for disease recurrence using a variety of scanning modalities and serum thyroglobulin. The accuracy of both the preoperative testing and postoperative monitoring is excellent in many cases; however, there are some important deficiencies that have led to the development new tools for clinical use. Specifically, the application of molecular methods to the analysis of pathology and blood samples has led to the development of highly sensitive markers for the diagnosis of new cases of thyroid cancer, and in the evaluation of patients for recurrent disease. In this review, the molecular analysis of thyroid nodules, lymph nodes and peripheral blood as adjunctive tests for thyroid cancer will be discussed.