Department of General, Visceral and Paediatric Surgery, University Hospital and Medical Faculty of the Heinrich-Heine University Düsseldorf, Düsseldorf, Germany.
Integrated BioBank of Luxembourg, Dudelange, Luxembourg.
Clin Chem. 2021 Mar 31;67(4):631-641. doi: 10.1093/clinchem/hvaa322.
Multiple technologies are available for detection of circulating tumor cells (CTCs), but standards to evaluate their technical performance are still lacking. This limits the applicability of CTC analysis in clinic routine. Therefore, in the context of the CANCER-ID consortium, we established a platform to assess technical validity of CTC detection methods in a European multi-center setting using non-small cell lung cancer (NSCLC) as a model.
We characterized multiple NSCLC cell lines to define cellular models distinct in their phenotype and molecular characteristics. Standardized tumor-cell-bearing blood samples were prepared at a central laboratory and sent to multiple European laboratories for processing according to standard operating procedures. The data were submitted via an online tool and centrally evaluated. Five CTC-enrichment technologies were tested.
We could identify 2 cytokeratin expressing cell lines with distinct levels of EpCAM expression: NCI-H441 (EpCAMhigh, CKpos) and NCI-H1563 (EpCAMlow, CKpos). Both spiked tumor cell lines were detected by all technologies except for the CellSearch system that failed to enrich EpCAMlow NCI-H1563 cells. Mean recovery rates ranged between 49% and 75% for NCI-H411 and 32% and 76% for NCI-H1563 and significant differences were observed between the tested methods.
This multi-national proficiency testing of CTC-enrichment technologies has importance in the establishment of guidelines for clinically applicable (pre)analytical workflows and the definition of minimal performance qualification requirements prior to clinical validation of technologies. It will remain in operation beyond the funding period of CANCER-ID in the context of the European Liquid Biopsy Society (ELBS).
有多种技术可用于检测循环肿瘤细胞（CTC），但仍缺乏评估其技术性能的标准。这限制了 CTC 分析在临床常规中的应用。因此，在 CANCER-ID 联盟的背景下，我们建立了一个平台，使用非小细胞肺癌（NSCLC）作为模型，在欧洲多中心环境中评估 CTC 检测方法的技术有效性。
我们对多个 NSCLC 细胞系进行了特征分析，以确定在表型和分子特征方面不同的细胞模型。在中央实验室制备了标准化的含肿瘤细胞血液样本，并按照标准操作规程发送到多个欧洲实验室进行处理。数据通过在线工具提交并进行集中评估。共测试了 5 种 CTC 富集技术。
我们能够鉴定出 2 种表达细胞角蛋白、具有不同 EpCAM 表达水平的 NSCLC 细胞系：NCI-H441（EpCAMhigh、CKpos）和 NCI-H1563（EpCAMlow、CKpos）。除 CellSearch 系统外，所有技术均能检测到两种掺入的肿瘤细胞系，而 CellSearch 系统未能富集 EpCAMlow 的 NCI-H1563 细胞。对于 NCI-H411，平均回收率在 49%到 75%之间，对于 NCI-H1563，平均回收率在 32%到 76%之间，并且在测试的方法之间观察到显著差异。
这项多国 CTC 富集技术能力验证对于建立适用于临床的（预）分析工作流程指南以及在技术临床验证之前定义最小性能资格要求具有重要意义。它将在 CANCER-ID 资助期结束后，在欧洲液体活检协会（ELBS）的背景下继续运作。
