Outcome of thyroid gene expression classifier testing in clinical practice

Laryngoscope. 2016 Feb;126(2):524-7. doi: 10.1002/lary.25607. Epub 2015 Sep 7.

Abstract

Objectives/hypothesis: Gene expression classifiers can safely reduce diagnostic thyroid surgery for fine-needle aspiration cytology (FNAC) indeterminate thyroid nodules.

Study design: Retrospective review, single-institution, single-practice surgeon.

Methods: Three-year retrospective review of indeterminate FNAC that went on to gene expression classifier testing.

Results: A total of 520 patients met American Thyroid Association guideline criteria for surgeon-performed ultrasound-guided FNAC for a thyroid nodule with on-site cytopathology. The indeterminate (Bethesda III or IV) FNAC rate was 9%. Prevalence of malignancy in FNAC indeterminate was 21%. Thirty-two cases went on to gene expression classifier testing. Fourteen were benign, 15 suspicious, and three with no result.

Conclusions: Benign gene expression classifier testing had an estimated negative predictive value of 100% during the study period. These patients have been observed for a mean and median duration of 14 and 7 months, respectively. In this small series, 14 of 29 patients with indeterminate FNAC were spared diagnostic surgery.

Level of evidence: 4.

Keywords: Thyroid; fine needle aspiration cytology; gene expression testing.

MeSH terms

  • DNA / genetics*
  • Diagnosis, Differential
  • Endoscopic Ultrasound-Guided Fine Needle Aspiration
  • Gene Expression Profiling / methods*
  • Gene Expression Regulation*
  • Guideline Adherence*
  • Humans
  • Retrospective Studies
  • Thyroid Nodule / diagnosis*
  • Thyroid Nodule / genetics
  • Thyroid Nodule / surgery
  • Thyroidectomy / standards*

Substances

  • DNA