[Expert consensus on PD-L1 expression testing in non-small-cell lung cancer in China].

Cancer immunotherapy, especially the programmed death 1 (PD-1) and (or) programmed death ligand 1 (PD-L1) checkpoint inhibitors, has ushered in the modern oncology era and has achieved impressive success in the treatment of different tumors, including non-small-cell lung cancer (NSCLC). Yet, only a subset of patients achieved clinical benefit. Therefore, how to effectively screen the potential beneficiaries of PD-1 and (or) PD-L1 inhibitors has become a new challenge in the era of cancer immunotherapy. Clinical studies have shown that the expression level of PD-L1 in NSCLC is positively correlated with the efficacy of PD-1 and (or) PD-L1 inhibitors, and is one of the important predictive biomarkers. However, there are many challenges in PD-L1 testing. With the approving of various PD-1 and (or) PD-L1 inhibitors for immunotherapy setting of NSCLC, expert consensus of important issues regarding clinical significance of PD-L1 testing, testing time-point, as well as the standardization of PD-L1 testing procedure, including the PD-L1 testing operation steps, results' interpretation, quality control and so on, is of great significance for improving the accuracy of detection and reducing the difference between laboratories. On account to the practical questions of PD-L1 testing, this consensus was finally reached, which is based on the combination of literature, expert experience and internal discussion among committee members, in the hope of providing the guide for standardizing the PD-L1 testing and providing accurate and reliable result to screen the potential patients and predict clinical efficacy. It must be pointed out that in view of the existence of objective and complex factors of PD-L1 testing and the fact that the clinical application of PD-L1 testing is still at the early stage in China, there are still many issues need to be updated in near future based on further practice experience and research data.免疫治疗，尤其是程序性死亡受体1(PD－1)和(或)程序性死亡配体1(PD－L1)免疫检查点抑制剂，重塑了肿瘤治疗模式，在包括非小细胞肺癌(NSCLC)在内的多种肿瘤治疗中部分患者均获得了显著的临床获益。如何筛选PD－1和(或)PD－L1抑制剂潜在获益人群成为免疫治疗时代面临的新挑战。NSCLC中PD－L1蛋白表达水平与PD－1和(或)PD－L1抑制剂疗效呈正相关，是重要的预测标志物之一。明确PD－L1检测的临床意义和检测时机，在PD－L1检测步骤、结果判读和质量控制等各个环节实现PD－L1检测的规范化和标准化，对提高检测的准确性和降低室间差异具有重要意义。针对PD－L1检测的实际问题，在结合文献、专家经验和委员会成员内部讨论基础上，最终达成此共识，以期规范PD－L1检测，为临床医师提供准确可靠的治疗依据以及给予临床检测一定的指导。必须指出的是，鉴于PD－L1检测客观复杂因素的存在以及国内PD－L1检测尚处于临床应用初期，此专家共识尚存在不足之处，期待未来有更多的研究和实践数据进一步完善。.