Division of Pathology and Laboratory Medicine, Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Cancer Cytopathol. 2018 May;126(5):342-352. doi: 10.1002/cncy.21987. Epub 2018 Mar 2.
Immune checkpoint inhibitors targeting the programmed cell death 1 (PD-1) receptor and its ligand, programmed death ligand 1 (PD-L1), have emerged as a therapeutic approach for patients with non-small cell lung carcinoma (NSCLC). PD-L1 expression, assessed by immunohistochemistry (IHC), is used to select patients for PD-1/PD-L1 inhibitor therapy. Most studies have been performed with histology specimens, with limited data available on the performance in cytology specimens. This study evaluated PD-L1 in cytology specimens and compared the results with those from paired core-needle biopsy for concordance.
Forty-one NSCLC fine-needle aspiration cases that had paired core-needle biopsy specimens with PD-L1 IHC were selected. A Papanicolaou-stained direct smear and a cell block section from each case were stained with a Dako PD-L1 pharmDx antibody (clone 22C3). Only slides with 100 or more tumor cells (37 smears and 38 cell blocks) were evaluated. Tumor proportion scores (TPS) were assessed on the basis of the partial/complete membranous staining of tumor cells and were correlated with those of paired core-needle biopsy.
All 9 smears that were negative for PD-L1 staining showed 100% concordance with the paired core-needle biopsy, whereas 28 smears with PD-L1 expression showed a similar TPS, except for 1 smear that was discordant. In contrast, 10 negative paired core-needle biopsy cases corresponded to 9 concordant negative cell blocks, whereas 1 cell block had a TPS of 1% to 5%. The remaining 28 cell blocks demonstrated PD-L1 expression, with 22 cases showing a TPS similar to that of the paired core-needle biopsy, whereas 6 cell blocks were discordant, likely because of intratumoral heterogeneity.
The results show that NSCLC cytology samples evaluated for PD-L1 have high concordance with paired core-needle biopsy samples and can be used for assessing PD-L1 expression. Cancer Cytopathol 2018;126:342-52. © 2018 American Cancer Society.
针对程序性细胞死亡 1 (PD-1) 受体及其配体程序性死亡配体 1 (PD-L1) 的免疫检查点抑制剂已成为非小细胞肺癌 (NSCLC) 患者的一种治疗方法。免疫组织化学 (IHC) 评估的 PD-L1 表达用于选择接受 PD-1/PD-L1 抑制剂治疗的患者。大多数研究都是使用组织学标本进行的，关于细胞学标本的检测性能数据有限。本研究评估了细胞学标本中的 PD-L1，并比较了与配对核心针活检结果的一致性。
选择了 41 例 NSCLC 细针抽吸病例，这些病例均有配对的核心针活检标本进行 PD-L1 IHC 检测。每个病例的巴氏染色直接涂片和细胞块切片均用 Dako PD-L1 pharmDx 抗体 (克隆 22C3) 染色。仅评估有 100 个或更多肿瘤细胞的切片 (37 张涂片和 38 个细胞块)。根据肿瘤细胞的部分/完全膜染色评估肿瘤比例评分 (TPS)，并与配对核心针活检进行相关性分析。
所有 9 例 PD-L1 染色阴性的涂片与配对核心针活检均显示 100%一致性，而 28 例 PD-L1 表达的涂片除 1 例不一致外，均显示相似的 TPS。相比之下，10 例 PD-L1 表达阴性的配对核心针活检病例与 9 例一致的阴性细胞块相对应，而 1 例细胞块的 TPS 为 1%至 5%。其余 28 例细胞块显示 PD-L1 表达，其中 22 例与配对核心针活检的 TPS 相似，而 6 例细胞块不一致，可能是由于肿瘤内异质性。
结果表明，评估 PD-L1 的 NSCLC 细胞学样本与配对核心针活检样本具有高度一致性，可用于评估 PD-L1 表达。癌症细胞病理学 2018;126:342-52. © 2018 美国癌症协会。
