Department of Pathology, Yonsei University College of Medicine, Seoul, South Korea.
PLoS One. 2024 Oct 10;19(10):e0309170. doi: 10.1371/journal.pone.0309170. eCollection 2024.
The purpose of this study was to investigate the expression of PD-L1 in invasive lobular carcinoma (ILC) and to determine its implications.
Tissue microarrays were constructed for 101 cases of ILC, and immunohistochemical staining for PD-L1 (using 22C3, SP142, and SP263 antibodies) was performed to examine the correlation between staining results and clinicopathologic parameters.
The positive cut-off values were defined as tumor cell (TC)≥1%, immune cell (IC)>0%, and IC≥1%. The range of PD-L1 TC positivity was 0.0-2.0%, with PD-L1 SP263 TC showing the highest positivity of 2.0%. The range of PD-L1 IC positivity was 0-21.8% for IC ≥ 1%, with PD-L1 22C3 IC showing the highest positivity. When PD-L1 IC was positive (IC≥1%), the highest antibody agreement was observed between SP263 and SP142 (OA = 93.1%), while the lowest agreement was observed between 22C3 and SP263 (OA = 73.3%, κ = 0.040). PD-L1 22C3 IC positivity (≥1%) was associated with high nuclear grade (p = 0.002), HER-2 positivity (p = 0.019), and pleomorphic type (p = 0.002).
PD-L1 expression in ILC shows a low TC positivity rate (0-2%) with various antibody clones and a variable IC positivity rate (0-21.8%). Pleomorphic type ILC exhibits higher PD-L1 IC positivity.
本研究旨在探讨 PD-L1 在浸润性小叶癌（ILC）中的表达及其意义。
构建了 101 例 ILC 的组织微阵列，并进行 PD-L1（使用 22C3、SP142 和 SP263 抗体）免疫组织化学染色，以检查染色结果与临床病理参数之间的相关性。
阳性截断值定义为肿瘤细胞（TC）≥1%，免疫细胞（IC）>0%，IC≥1%。PD-L1 TC 阳性率范围为 0.0-2.0%，PD-L1 SP263 TC 阳性率最高为 2.0%。PD-L1 IC 阳性率范围为 IC≥1%时为 0-21.8%，其中 PD-L1 22C3 IC 阳性率最高。当 PD-L1 IC 阳性（IC≥1%）时，SP263 和 SP142 之间的抗体一致性最高（OA=93.1%），而 22C3 和 SP263 之间的一致性最低（OA=73.3%，κ=0.040）。PD-L1 22C3 IC 阳性（≥1%）与核分级高（p=0.002）、HER-2 阳性（p=0.019）和多形性类型（p=0.002）相关。
ILC 中 PD-L1 的表达表现为 TC 阳性率低（0-2%），不同抗体克隆的 IC 阳性率（0-21.8%）也各不相同。多形性 ILC 表现出更高的 PD-L1 IC 阳性率。
