Has Afirma gene expression classifier testing refined the indeterminate thyroid category in cytology?. Issue 2 (30th September 2015)

• Record Type: Journal Article
• Authors: Yang, Sung‐Eun; Sullivan, Peggy S.; Zhang, Jianhua; Govind, Rekha; Levin, Mary R.; Rao, Jian‐Yu; Moatamed, Neda A.
• Is Part Of: Cancer cytopathology. Volume 124:Issue 2(2016)
• Page Start: 100
• Page End: 109
• Publication Date: 2015-09-30
• Subjects: Afirma -- atypia of undetermined significance -- fine‐needle aspiration -- follicular lesion of undetermined significance -- follicular neoplasia -- gene expression classifier -- indeterminate cytology -- thyroid; Cancer -- Cytopathology -- Periodicals; Pathology, Cellular -- Periodicals; Cytology -- Technique -- Periodicals; 611.01815
• DOI: 10.1002/cncy.21624
• Languages: English
• ISSNs: 1934-662X

Abstract

Abstract : BACKGROUND: Thyroid fine‐needle aspiration (FNA) plays a pivotal role in the evaluation of thyroid nodules. Up to 30% of cases are diagnosed as indeterminate by FNA, including atypia of undetermined significance, follicular lesion of undetermined significance, suspicious for a follicular neoplasm, and follicular neoplasm, with approximately two‐thirds having a benign outcome. The gene expression classifier (GEC) test is a molecular test for cases with indeterminate cytology. The purpose of the current study was to examine the refining role of the GEC test within a single institution. METHODS: Retrospective analysis of all thyroid FNAs during a 20‐month period after implementation of GEC was performed. Cases of indeterminate cytology with concomitant GEC testing were selected and divided further in 4 subgroups. Correlation with surgical follow‐up, when available, was performed. The results were compared with previously published data from the study institution before the implementation of GEC testing. RESULTS: Among the 217 cases, there were 189 with indeterminate cytology, 42% of which were benign and 50% of which were suspicious by GEC. The excisional rate of atypia of undetermined significance‐follicular lesion of undetermined significance in the pre‐GEC category was 63%, which decreased to 35% in the post‐GEC category, whereas the malignancy rate in the excised thyroids increased from 35% in the pre‐GEC category to 47% in the post‐GEC category. Similar findings also were obtained for suspicious for a follicular neoplasm‐follicular neoplasm lesions. CONCLUSIONS: The strength of the GEC test appears to lie in its ability to reclassify 42% of indeterminate cytology cases as benign, thereby decreasing the number of unnecessary surgical procedures. Cancer (Cancer Cytopathol) 2016;124:100–109. © 2015 American Cancer Society . Abstract : The Afirma gene expression classifier is a molecular test for thyroid fine‐needle aspiration specimens with an indeterminate cytologic diagnosis. Comparison of a single institution's characteristics before and after the introduction of the gene expression classifier test further defines implications for the test in patient care.