A clinical algorithm for fine-needle aspiration molecular testing effectively guides the appropriate extent of...

Area of Science:

• Endocrinology
• Surgical Oncology
• Molecular Diagnostics

Background:

• Differentiated thyroid cancer diagnosis often requires total thyroidectomy (TT) or lobectomy.
• Determining the appropriate initial extent of thyroid surgery presents a clinical challenge.

Purpose of the Study:

• To evaluate if a clinical algorithm incorporating molecular testing (MT) of fine-needle aspiration biopsy (FNAB) specimens guides initial total thyroidectomy (TT) for clinically significant thyroid cancer (sTC).
• To assess if MT correctly limits surgery to lobectomy when appropriate for thyroid nodules.

Main Methods:

• A prospective cohort study of 671 patients undergoing thyroidectomy with non-malignant cytology was conducted.
• Molecular testing (MT) was performed on FNAB specimens for a multigene panel in cohort 1.
• Positive MT results guided initial TT, while cohort 2 had no MT or unevaluable results.

Main Results:

• MT guidance correlated with a higher incidence of sTC after TT (P = 0.006) and a lower rate of sTC after lobectomy (P = 0.03).
• Patients with indeterminate cytology undergoing lobectomy without MT were 2.5 times more likely to require a second surgery for sTC (P < 0.001).
• Lobectomy was performed more appropriately in patients with non-sTC when routine preoperative MT was utilized (P = 0.001).

Conclusions:

• FNAB MT for specific gene mutations (BRAF, RAS, PAX8-PPARγ, RET-PTC) facilitates optimal initial surgical management for differentiated thyroid cancer.
• This approach streamlines definitive treatment for patients with thyroid nodules.