Korean journal of Endocrine Surgery (대한내분비외과학회지), Vol.15(3) : 53~59, 2015
With increasing prevalence of thyroid nodules, clinicians are increasingly impelled to identify the optimal predictor of thyroid cancer, with the goal of guiding management based on assessed risk. Fine-needle aspiration cytology is the gold standard diagnostic method for thyroid nodules. However, fine-needle aspiration cytology is not perfect and adjuncts which might complement its predictive value are being investigated from several innovative perspectives. For these vigorous efforts, remarkable advances have been achieved in understanding several major biologic areas of thyroid cancer, including the molecular alterations for loss of radioiodine avidity of thyroid cancer, the pathogenic role of the MAP kinase and PI3K/Akt pathways and their related genetic alterations in thyroid tumorigenesis and pathogenesis. These exciting advances provide unprecedented opportunities for development of molecular-based novel diagnostic and therapeutic strategies for thyroid cancer. The common somatic genetic changes in thyroid cancer of follicular cell origin (RET/PTC, NTRK, RAS, BRAF, PAX8-PPARγ) are generally mutually exclusive, with distinct genotype–histologic subtype associations of thyroid cancer. Mutation analysis in fine needle aspiration samples has been applied to improve the diagnostic accuracy. In studies regarding gene expression profiling, aberrant gene methylation and miRNA have shown significant progress toward identification of biomarkers that could improve the accuracy of fine needle aspiration cytology in the evaluation of patients with thyroid nodule and prediction of disease aggressiveness. Future clinical trials evaluating the accuracy and cost-effectiveness of applying these biomarkers in the management of thyroid neoplasm should be considered.