From the Department of Pathology, NYU School of Medicine, New York, New York (Devereaux), College of American Pathologists, Northfield, Illinois.
Biostatistics Department (Souers), College of American Pathologists, Northfield, Illinois.
Arch Pathol Lab Med. 2023 Apr 1;147(4):425-433. doi: 10.5858/arpa.2021-0585-CP.
CONTEXT.—: Clinical testing for tumor cell-free DNA (cfDNA) has evolved rapidly, but no practice guidelines exist.
OBJECTIVE.—: To summarize cfDNA laboratory practices based on self-reporting and assess preanalytical, analytical, and postanalytical trends that may influence the quality, accuracy, and consistency of cfDNA testing.
DESIGN.—: Data were derived from the College of American Pathologists cfDNA proficiency testing program submitted by 101 participating laboratories from 2018 to 2019.
RESULTS.—: Most laboratories performing clinical circulating tumor DNA testing are commercial/nonhospital (71.2%; 72 of 101) and international (77.2%; 78 of 101) laboratories. Commercial laboratories had higher monthly test volumes than hospital-based laboratories (median, 36 versus 7-8) and tended to have larger gene panels (median, 50 versus 11 genes) when panel-based testing was offered. The main clinical indications include therapy selection and treatment/disease monitoring. Plasma is the most commonly accepted specimen, which is predominantly collected in cell-stabilizing tubes. Equal proportions of laboratories use next-generation sequencing (NGS) and non-NGS methods to assess key genes, including EGFR, BRAF, KRAS, NRAS, and IDH1. Most laboratories reported a lower limit of detection (LLOD) of 0.5%, variant allele frequency or less, which did not differ by method, NGS or non-NGS, except for EGFR. Sixty-five percent (17 of 26) of laboratories using the US Food and Drug Administration (FDA)-approved non-NGS EGFR assay report analytical sensitivities higher than 0.5%, as compared to 15% (16 of 104) of laboratories using an alternative NGS or non-NGS method. There is also a wider range in LLODs obtained for the FDA-approved EGFR assay than nonapproved assays.
CONCLUSIONS.—: These results highlight emerging practice trends and serve as a foundation to initiate future practice recommendations.
肿瘤游离 DNA（cfDNA）的临床检测发展迅速，但目前尚无实践指南。
根据自我报告总结 cfDNA 实验室实践，并评估可能影响 cfDNA 检测质量、准确性和一致性的分析前、分析中和分析后趋势。
数据来自美国病理学家学院 2018 年至 2019 年期间参加 cfDNA 能力验证计划的 101 个参与实验室提交的数据。
进行临床循环肿瘤 DNA 检测的大多数实验室为商业/非医院实验室（71.2%；101 个实验室中有 72 个）和国际实验室（77.2%；101 个实验室中有 78 个）。商业实验室的月检测量高于医院实验室（中位数分别为 36 和 7-8），并且当提供基于面板的检测时，商业实验室的基因面板通常更大（中位数分别为 50 和 11 个基因）。主要的临床适应证包括治疗选择以及治疗/疾病监测。血浆是最常接受的标本，主要收集在细胞稳定管中。使用下一代测序（NGS）和非 NGS 方法评估关键基因（包括 EGFR、BRAF、KRAS、NRAS 和 IDH1）的实验室比例相等。大多数实验室报告检测下限（LLOQ）为 0.5%或更低，等位基因变异频率或更低，这与方法、NGS 或非 NGS 无关，除 EGFR 外。与使用替代 NGS 或非 NGS 方法的实验室相比，使用美国食品和药物管理局（FDA）批准的非 NGS EGFR 检测的 65%（26 个实验室中的 17 个）报告的分析灵敏度高于 0.5%，而使用替代 NGS 或非 NGS 方法的实验室为 15%（104 个实验室中的 16 个）。FDA 批准的 EGFR 检测获得的 LLOD 范围也比非批准的检测更广。
这些结果突出了新兴的实践趋势，并为未来的实践建议奠定了基础。
