Outcomes of repeat fineneedle aspiration biopsy for AUS/FLUS thyroid nodules

Abstract

Objective: To determine the proportion of aspirates reclassified into each Bethesda category and to assess the rates of malignancy in each of them on repeat fine-needle aspiration biop sy (RFNA) following an AUS/FLUS diagnosis. Design: Systematic review and meta-analysis Methods: On February 2019, Pubmed/MEDLINE, EMBASE, WoS, and the Cochran e Library were searched for articles published from January 1, 2007. All studies published in Englis h describing RFNA outcomes in AUS/FLUS nodules were included. PRISMA and MOOSE guidelines were followed. Five investigators independently assessed the eligibility of the studies. Two investigators extracted summary data and as sessed the risk of bias. Data were pooled using a random-effects model. The rate of malignancy was calculated on r esected nodules only (upper limit of true value); and considering all unresected nodules were benign (lower limit of true value). The protocol was registered in PROSPERO (CRD42019123114). Results: Of 2937 retrieved studies, 27 were eligible. The meta-analysis was conducted on summary data of 3932 AUS/FLUS thyroid nodules with RFNA. RFNA cytology would reclass ify into categories I through VI of Bethesda: 4% (3%, 5%), 48% (43%, 54%), 26% (20%, 32%), 4% (3%, 6%), 5% (3 %, 6%), and 2% (1%, 2%) of AUS/FLUS nodules. Malignancy rates of resected nodules were 24% (9%, 38%), 4% (1% , 7%), 40% (28%, 52%), 37% (27%, 47%), 79% (69%, 90%), and 99% (95%, 100%) for categories I through VI of Bethesda. There was high heterogeneity in these data. Conclusions: RFNA reclassified two-thirds of the AUS/FLUS specimens into a m ore definitive cytological category, with a benign call rate of nearly 50% and a negative predictive value greater than 96%.