Endocr Pract. 2019 Feb;25(2):161-164. doi: 10.4158/EP-2018-0395. Epub 2018 Nov 1.
The Veracyte Afirma Gene Expression Classifier (GEC) has been the most widely used negative predictive value molecular classifier for indeterminate cytology thyroid nodules since January 2011. To improve the specificity and further reduce unnecessary thyroid surgeries, a second-generation assay (Afirma Genetic Sequence Classifier [GSC]) was released for clinical use in August 2017. We report 11 months of clinical outcomes experience with the GSC and compare them to our 6.5-year experience with the GEC.
We searched our practice registry for FNAB nodules with Afirma results from January 2011through June 2018. GEC versus GSC results were compared overall, in oncocytic and nononcocytic aspirates and by pathologic outcomes.
GSC identified less indeterminate cytology nodules as suspicious (38.8%; 54/139) when compared to GEC (58.4%; 281/481). There was a decrease of in the percentage of oncocytic fine-needle aspiration thyroid biopsy (FNAB) subjects classified as suspicious in the GSC group, with 86 of 104 oncocytic indeterminates (82.7%) classified as suspicious by GEC and 12 of 34 (35.3%) classified as suspicious by GSC. The surgery rate in patients with oncocytic aspirates fell from 56% in the GEC group to 31% in the GSC-evaluated group (45%). Pathology analysis demonstrated a false-negative percentage for an incomplete surgical group of 9.5% for GEC and 1.2% for GSC.
Our GSC data suggest that the GSC further reduces surgery in indeterminate thyroid nodules by improving the specificity of Afirma technology without compromising sensitivity. A primary determinant for this change is a significant improvement in the specificity of the Afirma GSC test in oncocytic FNAB aspirates.
FNAB = fine-needle aspiration biopsy; GEC = Gene Expression Classifier; GSC = Genetic Sequence Classifier.
自 2011 年 1 月以来，Veracyte Afirma 基因表达分类器（GEC）一直是用于诊断不确定的甲状腺结节的最广泛使用的负预测值分子分类器。为了提高特异性并进一步减少不必要的甲状腺手术，第二代检测方法（Afirma 遗传序列分类器[GSC]）于 2017 年 8 月获准用于临床应用。我们报告了使用 GSC 的 11 个月临床结果，并将其与我们 6.5 年的 GEC 经验进行了比较。
我们在实践注册处中搜索了从 2011 年 1 月至 2018 年 6 月期间进行 Afirma 检查的细针抽吸活检（FNAB）结节。比较了 GEC 与 GSC 的总体结果、在嗜酸细胞和非嗜酸细胞抽吸物中的结果以及病理结果。
与 GEC（58.4%，281/481）相比，GSC 确定的可疑不确定细胞学结节较少（38.8%，54/139）。在 GSC 组中，嗜酸细胞细针抽吸甲状腺活检（FNAB）中可疑的分类减少，GEC 组 104 例嗜酸细胞不确定中 86 例（82.7%）可疑，GSC 组 34 例中 12 例（35.3%）可疑。GEC 组中嗜酸细胞抽吸物患者的手术率从 56%降至 GSC 评估组的 31%（45%）。病理分析显示，GEC 的不完全手术组的假阴性率为 9.5%，GSC 的假阴性率为 1.2%。
我们的 GSC 数据表明，通过提高 Afirma 技术的特异性，同时不影响敏感性，GSC 进一步减少了不确定的甲状腺结节的手术。这种变化的主要决定因素是 Afirma GSC 检测在嗜酸细胞 FNAB 抽吸物中的特异性显著提高。
FNAB = 细针抽吸活检；GEC = 基因表达分类器；GSC = 遗传序列分类器。
