Molecular Risk Stratification of Well-Differentiated Thyroid Cancer

Thyroid nodules are a common problem worldwide. The incidence and aetiology of nodule formation may vary by geography, but a common problem faced by all physicians is how to differentiate benign disease from malignancy. Clinical examination and ultrasonography may identify advanced thyroid carcinoma, but the diagnosis of the vast majority of well-differentiated thyroid cancers (WDTC) relies upon fine-needle aspiration biopsy (FNAB). Important advances in timely identification and management of thyroid cancer have been achieved by improvements in biopsy technique and standardization of thyroid cytopathology reporting. However, many patients still require a thyroid lobectomy before malignancy can be diagnosed. Minimizing the morbidity and cost of diagnostic surgery is an important goal given that the number of patients screened for thyroid malignancy continues to increase significantly across the world. In both the northern and southern hemispheres the incidence of thyroid cancer has more than doubled in the past two decades. Many investigators are now focusing their efforts on improving the diagnostic potential of aspiration biopsies through molecular diagnostics. Success in these efforts is reflected by the appearance of commercially available options for molecular diagnostics in thyroid nodule specimens. In the future, immunocytochemical markers combined with mutation analysis and large-scale genetic sequencing are likely to be used to define distinct benign and malignant signatures in thyroid neoplasms.