Surucu Ahmet, Hou Tieying, Kuhar Matthew, Durm Greg, Mesa Hector
Department of Pathology and Laboratory Medicine.
Division of Hematology/Oncology,Department of Medicine, Indiana University, School of Medicine, Indianapolis, IN.
Appl Immunohistochem Mol Morphol. 2023 Sep 1;31(8):550-554. doi: 10.1097/PAI.0000000000001140. Epub 2023 Jun 27.
PD-L1 IHC 22C3 pharmDx is an FDA-approved companion test to select patients for anti-PD-L1 immunotherapy. In head and neck squamous cell carcinoma PD-L1 expression is determined using a Combined Positive Score (CPS), which evaluates expression in tumor cells and tumor-associated leukocytes. We hypothesized that in nodal metastasis, the CPS should be higher given their inherent higher proportion of leukocytes. A significant difference in CPS between sites would mean that the tissue chosen for PD-L1 testing would impact patient eligibility for therapy. Currently, guidelines about which tissue should be tested do not exist. PD-L1 22C3 IHC was performed in the primary and nodal metastases of 35 head and neck squamous cell carcinoma, and a CPS was generated by 3 pathologists. Mean CPS was higher at the primary than the nodal metastasis: 47.2 versus 42.2; however, the difference was not statistically significant: P=0.259 . By therapeutic groups: negative (CPS <1), low (CPS 1-19) and high (CPS≥20), low-expression was more common in the primary: 40 vs. 26%, and high-expression in the nodal metastasis: 74 vs. 60% but this difference was not statistically significant: P=0.180. Stratified by positive versus negative (CPS <1 vs. ≥1), there were no differences between sites. Interobserver agreement for CPS among the 3 raters was slight for both sites: ƙ = 0.117 and 0.025, fair if stratified by therapeutic group: ƙ = 0.371 and 0.318, and near perfect if stratified as negative versus positive: ƙ = 0.652 and 1. There were no statistically significant differences in CPS between primary and nodal metastases independent of how the CPS was stratified.
PD-L1免疫组化22C3检测法(pharmDx)是一项经美国食品药品监督管理局(FDA)批准的伴随诊断检测,用于选择适合接受抗PD-L1免疫治疗的患者。在头颈部鳞状细胞癌中,使用综合阳性评分(CPS)来确定PD-L1表达,该评分评估肿瘤细胞和肿瘤相关白细胞中的表达情况。我们推测,在淋巴结转移中,由于其白细胞固有比例较高,CPS应该更高。不同部位之间CPS的显著差异意味着用于PD-L1检测的组织会影响患者的治疗资格。目前,尚无关于应检测何种组织的指南。对35例头颈部鳞状细胞癌的原发灶和淋巴结转移灶进行了PD-L1 22C3免疫组化检测,并由3名病理学家生成CPS。原发灶的平均CPS高于淋巴结转移灶:分别为47.2和42.2;然而,差异无统计学意义:P = 0.259。按治疗组分类:阴性(CPS <1)、低表达(CPS 1-19)和高表达(CPS≥20),原发灶中低表达更为常见:分别为40%和26%,淋巴结转移灶中高表达更为常见:分别为74%和60%,但差异无统计学意义:P = 0.180。按阳性与阴性(CPS <1与≥1)分层,不同部位之间无差异。3名评估者之间CPS的观察者间一致性在两个部位均为轻度:κ = 0.117和0.025,按治疗组分层时为中等:κ = 0.371和0.318,按阴性与阳性分层时接近完美:κ = 0.652和1。无论CPS如何分层,原发灶和淋巴结转移灶之间的CPS均无统计学显著差异。