Molecular testing and thyroid nodule management in North America

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Rising thyroid cancer incidence and evolving nomenclature (e.g., NIFTP) necessitate systematic patient evaluation.
• Thyroid neoplasia is a molecular event, requiring integrated diagnostic approaches.
• Advances in imaging (ultrasonography, ACR TI-RADS) aid nodule assessment and fine-needle aspiration (FNA) guidance.

Purpose of the Study:

• To evaluate the role of molecular testing in refining the risk of malignancy (ROM) for indeterminate thyroid FNA diagnoses.
• To compare the utility of common molecular platforms (Afirma GSC, ThyroSeq v3) in managing thyroid nodules.

Main Methods:

• Utilized The Bethesda System for Reporting Thyroid Cytology (BSRTC) for FNA specimen categorization.
• Employed molecular testing platforms (Veracyte Afirma GSC, ThyroSeq v3) on indeterminate cases (AUS/FLUS, FN/SFN).
• Integrated molecular results with clinical parameters for treatment recommendations.

Main Results:

• Negative molecular testing significantly reduces ROM for indeterminate diagnoses to 3-4%, similar to benign findings, supporting observation.
• Positive molecular results from Afirma GSC and ThyroSeq v3 indicate varying probabilities of cancer, requiring careful interpretation.
• Molecular test outcomes, alongside clinical data, are crucial for surgical decision-making.

Conclusions:

• Molecular testing is a valuable tool for managing indeterminate thyroid FNA results, improving diagnostic accuracy.
• Negative molecular tests support conservative management (observation) for many patients.
• Positive molecular results necessitate a comprehensive approach, integrating test findings with clinical and imaging data to guide surgical intervention.