Department of Anatomopathology, Tenon University Hospital, Assistance publique des Hopitaux de Paris (APHP.6), Sorbonne Université, Paris.
Gynecologic and Obstetrics Department, Tenon University Hospital, Assistance publique des Hôpitaux de Paris (APHP.6), Sorbonne Université, Paris.
Eur J Histochem. 2021 Mar 10;65(1):3185. doi: 10.4081/ejh.2021.3185.
Therapeutic strategies for epithelial ovarian cancers are evolving with the advent of immunotherapy, such as PD-L1 inhibitors, with encouraging results. However, little data are available on PDL-1 expression in ovarian cancers. Thus, we set out to determine the PD-L1 expression according to histological subtype. We evaluated the expression of two PD-L1 clones - QR1 and E1L3N - with two scores, one based on the percentage of labeled tumor cells (tumor proportion score, TPS) and the other on labeled immune cells (combined proportion score, CPS) in a consecutive retrospective series of 232 ovarian cancers. PD-L1 expression was more frequent in high grade serous carcinoma (27.5% with E1L3N clone and 41.5% with QR1 clone), grade 3 endometrioid carcinoma (25% with E1L3N clone and 50% with QR1 clone), and clear-cell carcinomas (27.3% with E1L3N clone and 29.6% with QR1 clone) than other histological subtypes with CPS score. Using the CPS score, 17% of cases were labeled with E1L3N vs 28% with QR1. Using the TPS score, 14% of cases were positive to E1L3N vs 17% for QR1. For TPS and CPS, respectively, 77% and 78% of the QR1 cases were concordant with E1L3N for the thresholds of 1%. Overall and progression-free survival between PD-L1 positive and PD-L1 negative patients were not different across all histological types, and each subtype in particular for serous carcinomas expressing PD-L1. Expression of PD-L1 is relatively uncommon in epithelium ovarian tumors. When positive, usually <10% of tumor cells are labeled. QR1 clone and CPS appear the best tools to evaluate PD-L1 expression.
随着免疫疗法的出现，如 PD-L1 抑制剂，上皮性卵巢癌的治疗策略正在不断发展，并取得了令人鼓舞的结果。然而，关于卵巢癌中 PD-L1 的表达数据很少。因此，我们着手根据组织学亚型确定 PD-L1 的表达。我们评估了两种 PD-L1 克隆（QR1 和 E1L3N）的表达，使用两个评分系统，一个基于标记肿瘤细胞的百分比（肿瘤比例评分，TPS），另一个基于标记免疫细胞的百分比（综合比例评分，CPS），对 232 例卵巢癌进行了连续回顾性研究。PD-L1 的表达在高级别浆液性癌（E1L3N 克隆的 27.5%和 QR1 克隆的 41.5%）、3 级子宫内膜样癌（E1L3N 克隆的 25%和 QR1 克隆的 50%）和透明细胞癌（E1L3N 克隆的 27.3%和 QR1 克隆的 29.6%）中比其他组织学亚型更为常见，CPS 评分。使用 CPS 评分，17%的病例用 E1L3N 标记，28%的病例用 QR1 标记。使用 TPS 评分，E1L3N 阳性的病例有 14%，QR1 阳性的病例有 17%。对于 TPS 和 CPS，QR1 病例的 77%和 78%与 E1L3N 的 1%阈值一致。在所有组织学类型中，PD-L1 阳性和 PD-L1 阴性患者的总生存率和无进展生存率无差异，特别是在表达 PD-L1 的浆液性癌中。PD-L1 在卵巢上皮性肿瘤中表达相对较少。当阳性时，通常只有<10%的肿瘤细胞被标记。QR1 克隆和 CPS 似乎是评估 PD-L1 表达的最佳工具。
