Positive predictive value of the Afirma gene sequencing classifier for evaluation of the indeterminate thyroid nodule: An institutional experience.

BACKGROUND

The purpose of this study was to determine the positive predictive value (PPV) and false positive (FP) rate for the Afirma Gene Sequencing Classifier (GSC).

METHODS

The GSC was analyzed in patients with indeterminate thyroid nodules (ITN). True positive (TP), FP and PPV were determined and were correlated with pathology.

RESULTS

From June 2023-January 2025, 75 ITN were evaluated with the GSC and it was suspicious for cancer in 21 (28 ​%); 15 patients with 16 suspicious nodules underwent thyroidectomy. There were 7 ​TP and 9 FP results for a PPV of 44 ​%. The final pathology was papillary cancer 6 and oncocytic carcinoma 1 with TP GSC and follicular/oncocytic adenoma 4, follicular nodule 2, NIFTP 2 and Hashimoto thyroiditis 1 with FP GSC.

CONCLUSIONS

A PPV of 44 ​% for the GSC has implications for the extent of surgery and for reducing overtreatment of patients with ITN.