Department of Pathology, Yonsei University College of Medicine, Seoul, South Korea.
BMC Cancer. 2024 Jun 6;24(1):689. doi: 10.1186/s12885-024-12437-w.
We examined the expression of programmed death-ligand 1 (PD-L1) in carcinoma of unknown primary (CUP) and its potential implications. Tissue microarrays were constructed for 72 CUP cases (histologic subtypes: 22 adenocarcinoma, 15 poorly differentiated carcinoma, 19 squamous cell carcinoma, and 14 undifferentiated carcinoma; clinical subtype: favorable type 17 [23.6%], unfavorable type 55 [76.4%]), with immunohistochemical staining performed for PD-L1 (22C3, SP142, SP263, and 28 - 8), CK7, and CK20 to determine the association between staining results and clinicopathological parameters. In CUP, the PD-L1 positivity rate was 5.6-48.6% (tumor cells [TC] or tumor proportion score [TPS]: 5.6-36.1%, immune cell score [IC]: 8.3-48.6%, combined positive score [CPS]: 16.7%) using different cutoff values for 22C3 (TPS ≥ 1%, CPS ≥ 10), SP142 (TC ≥ 50%, IC ≥ 10%), SP263, and 28 - 8 (TC and IC ≥ 1%). PD-L1 SP142 TC and PD-L1 SP263 IC showed the lowest (5.6%) and highest (48.6%) positivity rates, respectively. The PD-L1 positivity rate did not significantly differ based on the histologic subtype, clinical subtype, or CK7/CK20 across clones. Considering TC κ ≥ 1%, TC κ ≥ 50%, IC κ ≥ 1%, and IC κ ≥ 10%, the PD-L1 positivity rate was TC = 4.2-36.1% and IC = 9.7-48.6%; the overall agreement between antibodies ranged from 69.4 to 93.1%, showing fair or better agreement (κ ≥ 0.21). In CUP, PD-L1 positivity varied depending on antibodies and scoring systems, with no difference observed according to histologic or clinical subtypes.
我们研究了程序性死亡配体 1（PD-L1）在不明原发癌（CUP）中的表达及其潜在意义。为 72 例 CUP 病例（组织学亚型：22 例腺癌、15 例低分化癌、19 例鳞状细胞癌和 14 例未分化癌；临床亚型：有利型 17 例[23.6%]，不利型 55 例[76.4%]）构建了组织微阵列，并进行了 PD-L1（22C3、SP142、SP263 和 28-8）、CK7 和 CK20 的免疫组织化学染色，以确定染色结果与临床病理参数之间的关系。在 CUP 中，使用不同的 22C3（TPS≥1%，CPS≥10%）、SP142（TC≥50%，IC≥10%）、SP263 和 28-8（TC 和 IC≥1%）的截断值，PD-L1 阳性率为 5.6%-48.6%（肿瘤细胞[TC]或肿瘤比例评分[TPS]：5.6%-36.1%，免疫细胞评分[IC]：8.3%-48.6%，联合阳性评分[CPS]：16.7%）。PD-L1 SP142 TC 和 PD-L1 SP263 IC 的阳性率最低（5.6%）和最高（48.6%）。PD-L1 阳性率与克隆的组织学亚型、临床亚型或 CK7/CK20 无关。考虑到 TCκ≥1%、TCκ≥50%、ICκ≥1%和 ICκ≥10%，PD-L1 阳性率为 TC=4.2-36.1%和 IC=9.7-48.6%；抗体之间的总体一致性为 69.4%至 93.1%，显示出良好或更好的一致性（κ≥0.21）。在 CUP 中，PD-L1 阳性率因抗体和评分系统而异，与组织学或临床亚型无关。
