Resident, Department of Dermatology, University of California Irvine, Irvine, CA.
Research Fellow and Resident, School of Medicine, University of California Irvine, Irvine, CA.
Am J Dermatopathol. 2021 May 1;43(5):321-330. doi: 10.1097/DAD.0000000000001772.
PD-L1 and PD-1 inhibitors are being increasingly used to treat a variety of nonmelanoma skin cancers (NMSCs). This systematic review summarizes PD-L1 expression in NMSCs and determines its use for prognosis using targeted immunotherapy. A primary search of peer-reviewed English-language medical literature was conducted for studies on PD-L1 tumor expression in biopsied or excised NMSCs. Fifty-nine articles met criteria for inclusion. PD-L1 expression in advanced NMSCs ranged from 22%-89% for basal cell carcinomas, 42%-50% for Merkel cell carcinomas, and 26%-100% for squamous cell carcinomas. Study limitations included clone heterogeneity across studies, complicating comparison of PD-L1 expression. Differences were also noted in the selection of tumor reactivity threshold. We conclude that there is insufficient evidence to determine the prognostic significance of PD-L1 expression in NMSCs as a whole, but this remains a promising area. More investigation into the role of tumor PD-L1 as a biomarker for predicting clinical response to PD-L1 and PD-1 inhibitors in NMSCs is needed.
程序性死亡配体 1（PD-L1）和 PD-1 抑制剂正被越来越多地用于治疗各种非黑色素瘤皮肤癌（NMSC）。本系统综述总结了 NMSC 中 PD-L1 的表达情况，并确定了其在靶向免疫治疗中的预后应用。对同行评议的英文医学文献进行了初步检索，以寻找关于活检或切除的 NMSC 中 PD-L1 肿瘤表达的研究。有 59 篇文章符合纳入标准。晚期基底细胞癌、Merkel 细胞癌和鳞状细胞癌中 PD-L1 的表达率分别为 22%-89%、42%-50%和 26%-100%。研究局限性包括各研究之间的克隆异质性，这使得 PD-L1 表达的比较变得复杂。在肿瘤反应性阈值的选择上也存在差异。我们的结论是，目前尚无足够的证据确定 PD-L1 表达作为 NMSC 整体预后指标的意义，但这仍然是一个很有前途的领域。需要进一步研究肿瘤 PD-L1 作为预测 NMSC 对 PD-L1 和 PD-1 抑制剂临床反应的生物标志物的作用。
