Impact of the Gene Expression Classifier on Surgeon-Patient Decision Making in Indeterminate Thyroid Nodules

Abstract

Objectives:

1) Describe the impact the gene expression classifier has on management of indeterminate thyroid nodules. 2) Define patient and nodule characteristics which influence further testing with the gene expression classifier (GEC) versus diagnostic thyroidectomy (DT).

Methods:

A retrospective chart review was performed on 273 patients who underwent fine-needle aspiration (FNA) for thyroid nodules from November 2011 to January 2013. We further analyzed 68 patients with cytological indeterminate aspirates. These patients were offered serial observation with repeat FNA, GEC testing, or DT. Demographic data, cytologic and histologic findings, and management outcomes will be discussed.

Results:

In 68 patients with indeterminate cytology, 47% underwent GEC testing, 52% chose DT, and 1% elected for continued observation. The mean age in patients who underwent GEC testing was 57 years and 49 years in those who elected DT (p<0.05). Patients with a Bethesda classification of suspicious for malignancy were more likely to undergo DT, whereas those with a diagnosis of atypical of undetermined significance (AUS) or follicular neoplasm (FN) were more likely to obtain the GEC test (p<0.05). Those factors not found to be statistically significant were gender and size of the nodule (p>0.05). Thirty-seven percent of patients with an AUS or FN diagnosis who obtained the GEC test underwent a DT. However, of those patients with an AUS or FN diagnosis who did not obtain the GEC test, 97% underwent a DT (p<0.0001).

Conclusions:

Use of the GEC significantly reduced the surgical rate among patients with a Bethesda classification of AUS or FN.