Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy.
Division of Pathology, Central Hospital Bolzano, Bolzano, Italy.
Histopathology. 2022 Jan;80(2):397-406. doi: 10.1111/his.14562. Epub 2021 Nov 11.
The introduction of immunotherapy for patients with head and neck squamous cell carcinoma (HNSCC) raises the need for harmonisation between different types of antibody and immunohistochemistry platform for evaluating the expression of PD-L1 by use of the combined positive score (CPS) in this tumour. The aim of this study was to compare the expression of PD-L1 as determined with the CPS and two widely used assays (the 22C3 PharmDx assay and the SP263 assay) in a cohort of HNSCCs.
We analysed 43 whole sections of HNSCC with two different anti-PD-L1 antibodies, 22C3 and SP263. The results, expressed as the CPS, were evaluated by 10 trained pathologists and statistical analyses were performed. We found a very similar results for PD-L1 expression between the 22C3 PharmDx assay and the SP263 assay in our cohort, and a strong and significant correlation between the two assays for all specimens (P < 0.0001). The interobserver reliability among pathologists for the continuous scores of CPS with the intraclass correlation coefficient and the correlation between the two assays were both good. Moreover, the rate of agreement between assays was high at all cut-offs and was best for the most relevant cut-off of CPS ≥ 1, and the kappa values were always in the range of almost perfect.
Two different assays (the 22C3 PharmDx assay and SP263 assay) for PD-L1 in HNSCC showed high agreement. These data suggest that these two assays are interchangeable in the selection of patients with HNSCC for immunotherapy.
免疫疗法在头颈部鳞状细胞癌（HNSCC）患者中的引入提出了在不同类型的抗体和免疫组化平台之间进行协调的需要，以使用综合阳性评分（CPS）评估该肿瘤中 PD-L1 的表达。本研究的目的是比较 CPS 与两种广泛使用的检测方法（22C3 PharmDx 检测和 SP263 检测）在 HNSCC 队列中测定的 PD-L1 表达。
我们分析了 43 例 HNSCC 的全切片，使用了两种不同的抗 PD-L1 抗体 22C3 和 SP263。结果以 CPS 表示，由 10 名经过培训的病理学家进行评估，并进行了统计学分析。我们发现，在我们的队列中，22C3 PharmDx 检测和 SP263 检测的 PD-L1 表达结果非常相似，两种检测方法在所有标本之间均具有很强的显著相关性（P < 0.0001）。病理学家对 CPS 连续评分的观察者间可靠性和两种检测方法之间的相关性均良好。此外，在所有截止值下，两种检测方法之间的一致性率均较高，在最相关的 CPS≥1 截止值下最佳，kappa 值始终处于几乎完美的范围内。
两种不同的 HNSCC PD-L1 检测方法（22C3 PharmDx 检测和 SP263 检测）具有很高的一致性。这些数据表明，在选择接受免疫治疗的 HNSCC 患者时，这两种检测方法可以互换使用。
