COMMUNITY ENDOCRINE SURGICAL EXPERIENCE WITH FALSE-NEGATIVE AFIRMA GEC

Afirma Gene Expression ClassifierWe reviewed our community endocrine surgical practice database for patients who had undergone thyroid surgery from January 2011 through April 2017 despite benign Afirma GEC results.Afirma GEC testing was completed for 475 patients during the study period. Surgery was clinically indicated for other reasons in 42 of the 193 patients (22%) with Afirma GEC benign results. Malignancy or NIFTP in the targeted nodule was found in the final histologic evaluation of 14 of the 42 Afirma GEC benign surgical patients. The Afirma GEC false-negative percentage for our incomplete surgical group (FNP-ISG), defined as the surgically proven false negatives divided by the total Afirma GEC benign patients, was 7.3%.Our high surgical rate in Afirma GEC benign nodules reveals an FNP-ISG of 7.3% in our community endocrine surgical patient population; this value exceeds the 5.7% reported in the multicenter 2012 Afirma GEC validation study.Afirma GEC = Afirma Gene Expression Classifier; FNA = fine-needle aspiration; FNP = false-negative percentage; FNP-ISG = false-negative percentage for an incomplete surgical group; NIFTP = noninvasive follicular thyroid neoplasms with papillary-like nuclear features.