A Review of Thyroid Cancer

Abstract

To the Editor A recent Review 1 discussed the complexity of thyroid cancer. First, we would like to highlight the importance of distinguishing between benign and malignant thyroid nodules preoperatively.Approximately one-fourth of people worldwide have thyroid nodules, but only 10% to 15% of these nodules are malignant. 2,3 Therefore, when screening for thyroid malignancy in clinical practice, it is important to consider procedure invasiveness, diagnostic accuracy, and cost. 2 Second, we are surprised that the Review 1 did not mention immunohistochemical testing of fine-needle aspirates, especially for nodule classes III through IV of the Bethesda classification.Profiling thyroid nodules before surgery is important to help choose the correct treatment and follow-up plan. Many commercially available diagnostic tests have been developed to help clinicians in the preoperative characterization of thyroid nodules. In high-income countries, advanced in silico tests are available, and their costs are usually covered by private insurance companies; in public health care systems, the costs are supported by general taxation and out-of-pocket payments. It is important to combine diagnostic performance with cost-containing strategies to make thyroid nodule testing affordable, especially in low-and middle-income countries. The use of immunohistochemical testing on cytologically derived cell blocks is useful and cost-effective.Multicenter clinical trials have validated the reliability and diagnostic accuracy of galectin-3 expression analysis in assessment of thyroid cancer. 3,4 The accuracy and costeffectiveness of this diagnostic method, which can be improved by using a panel of thyroid nodule-associated mark-ers (eg, human bone marrow endothelial cell marker 1), have been recognized by the American Thyroid Association, especially in cases of cytologically indeterminate thyroid nodules. 5