Department of Pathology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Department of Pathology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
Cancer Res Treat. 2020 Jul;52(3):661-670. doi: 10.4143/crt.2019.718. Epub 2020 Jan 10.
We provide a comparison between 22C3 pharmDx and SP263 assay, for evaluating programmed death ligand 1 (PD-L1) expression in advanced gastric cancer (GC) patients.
The PD-L1 immunohistochemistry by 22C3 pharmDx and SP263 assays was performed in the center of the tumor (CT) and invasive margin (IM) in 379 GC tissues using tissue microarrays and interpreted as combined positive score (CPS) and tumor proportion score (TPS). Of the total samples, 55 samples were independently reviewed by five pathologists.
The two assays showed a high correlation in both the CPS and TPS. At a CPS ≥ 1 cut-off, 219 (57.8%) and 231 (60.9%) GCs were positive for PD-L1 with the 22C3 and SP263 assays, and at ≥ 10 cut-off, 37 (9.8%) and 36 (9.5%) GCs were positive, respectively. The overall percent agreement (OPA) was greater than 90% with CPS ≥ 1 and ≥ 10 cut-offs, and TPS ≥ 1% and ≥ 10% cut-offs. There was higher OPA between the two assays with a CPS cut-off ≥ 10 (99.2%) than ≥ 1 (94.7%). The percent agreement between the CT and IM was higher with a CPS cut-off ≥ 10 (92.9%) than ≥ 1 (77.6%). Patient with positive expression at CPS ≥ 5 cut-off had a significantly better outcomes in both assays. Interobserver variability among five pathologists was higher than the assay variability.
Two assays for PD-L1 expression in GC showed high agreement. These results provide guidance for selecting eligible patients with GC for pembrolizumab treatment.
我们比较了 22C3 pharmDx 和 SP263 检测方法，以评估晚期胃癌（GC）患者程序性死亡配体 1（PD-L1）的表达。
使用组织微阵列在肿瘤中心（CT）和浸润边缘（IM）对 379 例 GC 组织进行 22C3 pharmDx 和 SP263 检测的 PD-L1 免疫组化，并以综合阳性评分（CPS）和肿瘤比例评分（TPS）进行解读。在总样本中，55 例样本由 5 位病理学家进行独立复查。
两种检测方法在 CPS 和 TPS 中均显示出高度相关性。在 CPS≥1 截断值时，22C3 和 SP263 检测方法分别有 219（57.8%）和 231（60.9%）例 GC 为 PD-L1 阳性，在 CPS≥10 截断值时，分别有 37（9.8%）和 36（9.5%）例 GC 为 PD-L1 阳性。CPS≥1 和≥10 截断值时，总体一致性（OPA）大于 90%，TPS≥1%和≥10%截断值时，OPA 也大于 90%。在 CPS 截断值≥10 时，两种检测方法的 OPA 更高（99.2%），而 CPS 截断值≥1 时的 OPA 较低（94.7%）。在 CPS 截断值≥10 时，CT 和 IM 之间的一致性更高（92.9%），而 CPS 截断值≥1 时的一致性较低（77.6%）。两种检测方法均显示 CPS≥5 截断值的阳性表达患者的生存结果显著改善。五位病理学家之间的观察者间变异性高于检测方法的变异性。
两种 GC 中 PD-L1 表达的检测方法具有高度一致性。这些结果为选择适合接受 pembrolizumab 治疗的 GC 患者提供了指导。
