Department of Respiratory Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Department of Pathology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Cancer Med. 2024 Oct;13(19):e70078. doi: 10.1002/cam4.70078.
Circulating tumor DNA (ctDNA) has emerged as a promising biomarker for noninvasive cancer diagnostics, particularly in the context of metastatic non-small-cell lung cancer (NSCLC). Detecting targetable variants through ctDNA analysis offers the potential to guide treatment decisions, especially in cases where tissue samples are insufficient or unavailable.
In this study, we developed and validated a next-generation sequencing panel targeting 101 cancer-related genes (101-test) to detect somatic variants in ctDNA from a large cohort of Chinese patients with metastatic NSCLC. The performance of the 101-test was assessed by evaluating its limit of detection (LOD), accuracy, and precision in identifying molecular variants. Additionally, the concordance between ctDNA and tissue samples for detecting targetable variants was analyzed in 904 patients.
The 101-test demonstrated a LOD of 0.38% for single-nucleotide variants (SNVs), 0.33% for insertions and deletions (InDels), and 0.33% for fusions. Sensitivity was 98.3% for SNVs, 100% for InDels, and 100% for fusions when compared to digital droplet PCR (ddPCR)/breakpoint PCR reference methods. The by-variant sensitivity for somatic variants was 97.5%, with a specificity of 99.9% between tumor-only and tumor-normal analyses. In a real-world cohort, the concordance between ctDNA and tissue samples for identifying targetable variants was 72.2% (457/633). Notably, the EGFR S768I variant, recently recommended by clinical guidelines, achieved an 80% concordance rate. Furthermore, 4.3% of patients (27/633) with targetable variants were identified exclusively through ctDNA testing.
The ctDNA-based 101-test is a highly sensitive and specific tool for detecting targetable variants in metastatic NSCLC, particularly in cases with insufficient tissue samples. The findings support the use of ctDNA testing as a reliable and complementary method to traditional tissue-based molecular analysis, enhancing the precision of treatment strategies for NSCLC patients.
循环肿瘤 DNA（ctDNA）已成为一种有前途的非侵入性癌症诊断生物标志物，特别是在转移性非小细胞肺癌（NSCLC）的情况下。通过 ctDNA 分析检测可靶向的变体有可能指导治疗决策，特别是在组织样本不足或无法获得的情况下。
在这项研究中，我们开发并验证了一种靶向 101 个癌症相关基因的下一代测序 panel（101 测试），用于检测来自中国转移性 NSCLC 大患者队列的 ctDNA 中的体细胞变体。通过评估其在检测分子变体中的检测限（LOD）、准确性和精密度来评估 101 测试的性能。此外，在 904 名患者中分析了 ctDNA 与组织样本检测可靶向变体的一致性。
101 测试对单核苷酸变体（SNV）的 LOD 为 0.38%，对插入和缺失（InDels）的 LOD 为 0.33%，对融合的 LOD 为 0.33%。与数字液滴 PCR（ddPCR）/断点 PCR 参考方法相比，SNV 的敏感性为 98.3%，InDels 的敏感性为 100%，融合的敏感性为 100%。体细胞变体的按变体敏感性为 97.5%，肿瘤仅与肿瘤正常分析之间的特异性为 99.9%。在真实世界的队列中，ctDNA 与组织样本识别可靶向变体的一致性为 72.2%（457/633）。值得注意的是，最近临床指南推荐的 EGFR S768I 变体的一致性率为 80%。此外，通过 ctDNA 检测可靶向变体的患者比例为 4.3%（27/633）。
基于 ctDNA 的 101 测试是一种高度敏感和特异的检测转移性 NSCLC 中可靶向变体的工具，特别是在组织样本不足的情况下。这些发现支持将 ctDNA 检测作为传统基于组织的分子分析的可靠且互补方法，提高 NSCLC 患者治疗策略的准确性。
