Genetic Testing in Differentiated Thyroid Carcinoma: Indications and Clinical Implications

Differentiated thyroid cancer (DTC) is a common and diverse endocrine malignancy. In most patients DTC results in an indolent and curable disease. Nevertheless, disease recurrence rates are relatively high (10%–30%), while 5% of the patients are resistant to conventional treatment and some of these patients are incurable. Over the past 20 years much progress has been made in identifying genetic changes that occur in DTC. In addition, studies aimed to understand the role of these genetic changes in tumorigenesis and their effects on the clinical characteristics of the disease have been conducted. The accrued knowledge has set the stage for development of genetic tests aimed to identify these changes in samples obtained from DTC patients and use this information in the clinical decision process. This paper reviews genetic changes that were identified in DTC, and how the emerging data obtained by genetic testing are currently used to gain key information on the diagnosis, risk stratification, and personalized care of DTC patients.