1 Department of Surgery, Massachusetts General Hospital , Boston, Massachusetts.
2 Department of Pathology, Massachusetts General Hospital , Boston, Massachusetts.
Thyroid. 2015 Jul;25(7):789-96. doi: 10.1089/thy.2015.0049. Epub 2015 Jun 4.
The recently introduced Afirma gene expression classifier (AGEC) provides binary results (benign or suspicious) to guide management of cytologically indeterminate thyroid nodules. The AGEC is intended to reduce unnecessary surgeries for benign nodules, and management algorithms favor surgery for suspicious results. Limited data are available on the performance of this test for Hürthle cell nodules (HCNs). This study hypothesized that a predominance of Hürthle cells leads to an increased rate of suspicious AGEC results with a potential for overtreatment, despite a relatively low risk of malignancy.
The pathology databases from three tertiary care facilities were queried from 2010 to 2014 for fine-needle aspirates (FNAs) diagnosed as suspicious for Hürthle cell neoplasm (SHCN) or atypia of undetermined significance/follicular lesion of undetermined significance concerning for Hürthle cell neoplasm (AFHCN). Cytology diagnoses were rendered internally prior to AGEC testing. The patient demographics, FNA diagnosis, AGEC result, surgical procedure, and pathologic outcomes were recorded.
The cohort consisted of 134 patients with HCNs. Prior to AGEC availability, 62 patients underwent surgery: 81% (50/62) of patients had surgery, and 34% (17/50) of the resected index nodules were malignant. After introduction of the AGEC, 72 patients underwent AGEC testing: 65% (47/72) of patients had surgery, and 13% (6/46) of the resected nodules were malignant. Thirty-two percent (23/72) of patients had a benign AGEC result and did not undergo surgery, and 4% (3/72) had surgery despite a benign AGEC result with benign final pathology, whereas 63% (45/72) of patients had suspicious AGEC results, with 96% of these patients (43/45) undergoing surgery, and 14% (6/43) of these index nodules were malignant.
While 32% of tested patients declined surgery based on a benign AGEC, 86% of patients with suspicious AGEC findings had unnecessary surgery, reflecting a substantially lower rate of malignancy from what was previously reported for all indeterminate nodules. Given the approximate pretest malignancy risk of 25-35% for an FNA diagnosis of SHCN or AFHCN, a suspicious AGEC diagnosis does not increase the probability of malignancy in an HCN, and patients should be counseled accordingly.
最近推出的 Afirma 基因表达分类器（AGEC）提供了良性或可疑的二元结果，以指导对细胞学不确定的甲状腺结节的管理。AGEC 旨在减少对良性结节的不必要手术，并且管理算法支持对可疑结果进行手术。对于 Hurthle 细胞结节（HCN），有关该测试性能的可用数据有限。本研究假设 Hurthle 细胞的优势导致可疑的 AGEC 结果的发生率增加，存在过度治疗的可能性，尽管恶性肿瘤的风险相对较低。
从 2010 年至 2014 年，从三个三级保健机构的病理数据库中查询了细针抽吸术（FNA）诊断为 Hurthle 细胞肿瘤可疑（SHCN）或意义不明的不典型性/滤泡性病变可疑的 Hurthle 细胞肿瘤（AFHCN）。在进行 AGEC 检测之前，内部做出细胞学诊断。记录了患者人口统计学，FNA 诊断，AGEC 结果，手术程序和病理结果。
该队列包括 134 例 HCN 患者。在 AGEC 可用之前，有 62 例患者接受了手术：81％（50/62）的患者接受了手术，而切除的索引结节中有 34％（17/50）为恶性。在引入 AGEC 之后，有 72 例患者接受了 AGEC 测试：65％（47/72）的患者接受了手术，而切除的结节中有 13％（6/46）为恶性。32％（23/72）的患者 AGEC 结果为良性且未接受手术，而 4％（3/72）尽管 AGEC 结果为良性且最终病理为良性，仍接受了手术，而 63％（45/72）的患者 AGEC 结果为可疑，其中 96％（43/45）的患者接受了手术，而这些索引结节中有 14％（6/43）为恶性。
尽管有 32％的经测试患者因良性 AGEC 而拒绝手术，但 86％的可疑 AGEC 发现患者进行了不必要的手术，这反映了先前报告的所有不确定结节的恶性肿瘤发生率明显降低。鉴于 FNA 诊断为 SHCN 或 AFHCN 的术前恶性肿瘤风险约为 25-35％，可疑的 AGEC 诊断并不能增加 HCN 中恶性肿瘤的可能性，因此应相应地对患者进行咨询。
