滋养层抗原2（Trop2）是一种在多种癌症（包括乳腺癌、非小细胞肺癌和胃肠癌）中表达的细胞表面糖蛋白。Trop2的表达及其在胸腺上皮肿瘤（TETs）中的抗体药物结合物（ADC）等Trop2定向治疗的应用尚未进行研究。回顾性识别在MedStar乔治敦大学医院接受TETs治疗的患者。对于具有可供病理样本和正常胸腺组织的患者，进行了Trop2和PD-L1的免疫组化（IHC）膜状染色。Trop2的阳性要求至少10％的肿瘤细胞染色，并评分为1+（弱）、2+（中等）和3+（强烈）强度。CPS≥5％的病例被认为对PD-L1阳性。识别了29名患者（17名胸腺瘤患者和12名胸腺癌患者）的30个TET样本。其中一名胸腺癌患者有两个来自不同时间点的样本。从相同的患者样本中，获得了13个正常胸腺组织样本。在正常胸腺组织中，有8个样本（62％）未显示出Trop2的阳性，而有5个样本（38％）显示出1+的IHC染色。在胸腺瘤样本中，有4个样本（24％）显示0或1+的IHC染色，而有13个样本（76％）显示2+或3+的染色。在13个胸腺癌样本中，有3个样本（23％）显示1+的IHC染色，而有7个样本（54％）显示2+的染色，还有3个样本（23％）显示3+的染色。在胸腺瘤或胸腺癌中，PD-L1的表达与Trop-2的表达之间没有统计学显著相关性可见。Trop2在TETS中易表达，并在胸腺癌中表达程度较高。与TETs相比，正常胸腺组织中Trop-2的表达较低。TETs中Trop-2的增加表达表明Trop2是Trop-2定向治疗的一个有吸引力的治疗靶点。由Elsevier B.V.出版。

Trophoblastic antigen 2 (Trop2) is a cell surface glycoprotein expressed in multiple types of cancers, including breast cancer, non-small cell lung cancer, and gastrointestinal cancers. Trop2 expression and the use of Trop2-directed therapy such as antibody-drug conjugate (ADC) have not yet been investigated in thymic epithelial tumors (TETs).Patients with TETs treated at MedStar Georgetown University Hospital were retrospectively identified. Of the patients for whom tumor samples and normal thymus tissue were available, immunohistochemistry (IHC) membranous staining for Trop2 and PD-L1 were performed. Positivity for Trop2 required at least 10% of the tumor cells to be stained, with an intensity scored of 1+ (weak), 2+ (moderate), and 3+ (strong). Cases with CPS ≥ 5% were considered positive for PD-L1.30 TET samples from 29 patients (17 patients with thymoma and 12 patients with thymic carcinoma) were identified. One patient with thymic carcinoma had two samples from different time points. From the same set of patients, 13 samples of normal thymus tissue were available. In normal thymus tissue, eight samples (62%) showed no positivity of Trop2, while five samples (38%) showed 1 + IHC staining. In the thymoma samples, four (24%) showed 0 or 1 + IHC staining, while 13 (76%) showed 2 + or 3 + staining. Of the 13 thymic carcinoma samples, three samples (23%) showed 1 + IHC staining while seven (54%) showed 2 + staining and three (23%) showed 3 + staining. There was no statistically significant correlation found between PD-L1 expression and Trop-2 expression in thymoma or thymic carcinoma.Trop2 is readily expressed in TETS with a higher degree of expression in thymic carcinoma. The expression of Trop-2 was lower in normal thymic tissue compared with TETs. The increased expression of Trop-2 in TETs suggests that Trop2 is an attractive therapeutic target for Trop-2 directed therapy.Published by Elsevier B.V.