NTRK重排肿瘤虽然罕见，但可以通过抗TRK靶向治疗成功治疗，使NTRK检测成为治疗晚期癌症患者的重要选择。泛Trk免疫组化（IHC）已成为许多实验室宝贵且经济实惠的筛查工具。不幸的是，用于研究生物标志物的抗体和IHC协议的选择并未标准化。在本研究中，我们比较了四种泛Trk IHC方法的表现，使用了三种不同的克隆，主要针对NTRK融合阳性的肿瘤。我们研究了四种泛Trk IHC方法的表现，使用了三种不同的克隆：EPR17341（Abcam和Ventana）、EP1058Y（Abcam）和A7H6R（Cell Signaling），在22个分子确认的NTRK重排肿瘤中进行了研究。此外，还包括选择的NTRK融合阴性肿瘤：NTRK突变（n = 8）和扩增（n = 15）肿瘤以及由其他基因融合驱动的NTRK融合阴性肿瘤，如ALK、ROS1和BCOR（n = 20），以及涎腺肿瘤（n = 16）。此外，还计算了三名病理医师的互评一致性，包括H评分。使用EPR17341克隆（Abcam内部和即用型Ventana协议），所有分子确认的NTRK1-3重排肿瘤均可通过免疫组化检测到，而其他克隆则错过了NTRK2-3重排肿瘤。对于融合阴性队列，我们使用A7H6R（Cell Signaling）克隆表现最佳（假阳性最少）。鉴于治疗重要性，在日常实践中测试NTRK重排已变得必要，尽管IHC是一种快速且经济实惠的工具，但在日常诊断中使用它是复杂的，需要高水平的专业知识。©2023 The Authors。由约翰威立有限公司出版的组织病理学。

NTRK rearranged tumours are rare but can be successfully treated using anti-TRK-targeted therapies, making NTRK testing important for treatment choices in patients with advanced cancers. Pan-Trk immunohistochemistry (IHC) has become a valuable and affordable screening tool in many laboratories. Unfortunately, the choice of antibodies and IHC protocols to investigate biomarkers is not standardised. In this study, we compared the performance of four pan-Trk IHC methods, using three different clones, primarily in NTRK fusion-positive tumours.We studied the performance of four pan-Trk IHC methods using three different clones: EPR17341 (Abcam and Ventana), EP1058Y (Abcam) and A7H6R (Cell Signaling) in 22 molecularly confirmed NTRK rearranged tumours. Additionally, selected NTRK fusion-negative tumours were further included: NTRK mutated (n = 8) and amplified (n = 15) tumours as well as NTRK fusion-negative tumours driven by other gene fusions, such as ALK, ROS1 and BCOR (n = 20), as well as salivary gland tumours (n = 16). Inter-rater agreement of three pathologists was additionally calculated, including H-score. With clone EPR17341 (Abcam in-house and ready-to-use Ventana protocol), all molecularly confirmed NTRK1-3 rearranged tumours were positively detected by immunohistochemistry, while the other clones missed NTRK2-3 rearranged tumours. For the fusion-negative cohort we found the best performance (least false-positive cases) using the clone A7H6R (Cell Signalling).Given the therapeutic importance, testing for NTRK rearrangements in daily practice has become necessary and, despite IHC being a fast and affordable tool, using it in routine diagnostics is complicated and requires a high level of expertise.© 2023 The Authors. Histopathology published by John Wiley & Sons Ltd.