Department of Translational Medicine, Clinical Biomarkers and Companion Diagnostics, Merck KGaA, Darmstadt, Germany.
Department of Image Analysis Professional Services, Definiens GmbH, Munich, Germany.
J Pathol Clin Res. 2020 Apr;6(2):124-137. doi: 10.1002/cjp2.152. Epub 2020 Jan 10.
Anti-PD-1/PD-L1 immunotherapy could offer an alternative to traditional chemo- and/or radiotherapy to treat pediatric cancer patients. To unveil the potential benefit of this new therapeutic approach, the prevalence of PD-L1 and other relevant immune markers using quantitative digital image analysis (DIA) could help to clarify this point. A bridging study was first conducted using commercially available normal formalin-fixed paraffin-embedded (FFPE) tonsils to compare immunostaining patterns and intensities from PD-L1, tumor infiltrating lymphocyte (TIL) markers CD3, CD8, FoxP3, CD45RO, and macrophage marker CD68 in adult (n = 5) and pediatric (n = 10) samples. Then, commercially available pediatric FFPE tumor samples from five prevalent pediatric solid tumor indications: ganglioneuroblastoma (n = 7); neuroblastoma (n = 23); nephroblastoma (n = 30); osteosarcoma (n = 24); and rhabdomyosarcoma (n = 25) were immunostained and their images (n = 654) digitally analyzed using predefined algorithms. The qualitative analysis of staining patterns and intensities in all 15 tonsils for all 6 biomarkers was similar regardless of age category. Quantitative DIA showed that PD-L1 values varied across cancer-types, nephroblastoma having the lowest counts. PD-L1 counts in ganglioneuroblastoma, our pediatric indication with the highest average value, was approximately 12-times lower than in a similar nonsmall cell lung cancer study, an indication approved for anti-PD-1/PD-L1 immunotherapies. Variable values were measured for the TIL markers CD3, CD8, and CD45RO. FoxP3 was scant across all indications. The macrophage marker CD68 showed highest values in ganglioneuroblastoma, with lowest levels in nephroblastoma. In conclusion, the low PD-L1 levels uncorrelated with TIL values from the present biomarker morphological study suggest that a PD-L1 immunohistochemistry patient selection strategy used for anti-PD-1/PD-L1 monotherapy in adult tumors may not succeed in these pediatric indications.
抗 PD-1/PD-L1 免疫疗法可为儿科癌症患者提供替代传统化疗和/或放疗的治疗方法。为了揭示这种新治疗方法的潜在益处，使用定量数字图像分析 (DIA) 来检测 PD-L1 和其他相关免疫标志物的阳性率，可能有助于阐明这一点。本研究首先使用商业上可获得的正常福尔马林固定石蜡包埋 (FFPE) 扁桃体进行了桥接研究，以比较来自成人 (n=5) 和儿科 (n=10) 样本的 PD-L1、肿瘤浸润淋巴细胞 (TIL) 标志物 CD3、CD8、FoxP3、CD45RO 和巨噬细胞标志物 CD68 的免疫染色模式和强度。然后，对来自五种常见儿科实体瘤适应证的商业上可获得的儿科 FFPE 肿瘤样本进行免疫染色：神经母细胞瘤 (n=23)；神经节母细胞瘤 (n=7)；肾母细胞瘤 (n=30)；骨肉瘤 (n=24)；横纹肌肉瘤 (n=25)，并使用预定义的算法对其图像 (n=654) 进行数字分析。在所有 15 个扁桃体中，所有 6 种生物标志物的染色模式和强度的定性分析结果均与年龄类别无关。定量 DIA 显示 PD-L1 值因癌症类型而异，肾母细胞瘤的计数最低。在神经母细胞瘤中，我们的儿科适应证的平均 PD-L1 值最高，但与类似的非小细胞肺癌研究相比，其计数约低 12 倍，而非小细胞肺癌是批准抗 PD-1/PD-L1 免疫治疗的适应证。TIL 标志物 CD3、CD8 和 CD45RO 的测量值存在差异。FoxP3 在所有适应证中均很少见。巨噬细胞标志物 CD68 在神经母细胞瘤中显示出最高值，在肾母细胞瘤中显示出最低值。总之，本研究中生物标志物形态学研究中 PD-L1 水平低与 TIL 值无关，提示在成人肿瘤中使用 PD-L1 免疫组化患者选择策略进行抗 PD-1/PD-L1 单药治疗可能不适用于这些儿科适应证。
