Henriksen T V, Demuth C, Frydendahl A, Nors J, Nesic M, Rasmussen M H, Reinert T, Larsen O H, Jaensch C, Løve U S, Andersen P V, Kolbro T, Thorlacius-Ussing O, Monti A, Gögenur M, Kildsig J, Bondeven P, Schlesinger N H, Iversen L H, Gotschalck K A, Andersen C L
Department of Molecular Medicine, Aarhus University Hospital, Aarhus; Department of Clinical Medicine, Aarhus University, Aarhus.
Department of Surgery, Regional Hospital Gødstrup, Herning.
Ann Oncol. 2024 Feb;35(2):229-239. doi: 10.1016/j.annonc.2023.11.009. Epub 2023 Nov 21.
Increasingly, circulating tumor DNA (ctDNA) is proposed as a tool for minimal residual disease (MRD) assessment. Digital PCR (dPCR) offers low analysis costs and turnaround times of less than a day, making it ripe for clinical implementation. Here, we used tumor-informed dPCR for ctDNA detection in a large colorectal cancer (CRC) cohort to evaluate the potential for post-operative risk assessment and serial monitoring, and how the metastatic site may impact ctDNA detection. Additionally, we assessed how altering the ctDNA-calling algorithm could customize performance for different clinical settings.
Stage II-III CRC patients (N = 851) treated with a curative intent were recruited. Based on whole-exome sequencing on matched tumor and germline DNA, a mutational target was selected for dPCR analysis. Plasma samples (8 ml) were collected within 60 days after operation and-for a patient subset (n = 246)-every 3-4 months for up to 36 months. Single-target dPCR was used for ctDNA detection.
Both post-operative and serial ctDNA detection were prognostic of recurrence [hazard ratio (HR) = 11.3, 95% confidence interval (CI) 7.8-16.4, P < 0.001; HR = 30.7, 95% CI 20.2-46.7, P < 0.001], with a cumulative ctDNA detection rate of 87% at the end of sample collection in recurrence patients. The ctDNA growth rate was prognostic of survival (HR = 2.6, 95% CI 1.5-4.4, P = 0.001). In recurrence patients, post-operative ctDNA detection was challenging for lung metastases (4/21 detected) and peritoneal metastases (2/10 detected). By modifying the cut-off for calling a sample ctDNA positive, we were able to adjust the sensitivity and specificity of our test for different clinical contexts.
The presented results from 851 stage II-III CRC patients demonstrate that our personalized dPCR approach effectively detects MRD after operation and shows promise for serial ctDNA detection for recurrence surveillance. The ability to adjust sensitivity and specificity shows exciting potential to customize the ctDNA caller for specific clinical settings.
循环肿瘤DNA（ctDNA）越来越多地被提议作为一种用于微小残留病（MRD）评估的工具。数字PCR（dPCR）分析成本低，周转时间不到一天，使其具备临床应用的成熟条件。在此，我们在一个大型结直肠癌（CRC）队列中使用肿瘤知情的dPCR检测ctDNA，以评估术后风险评估和连续监测的潜力，以及转移部位如何影响ctDNA检测。此外，我们评估了改变ctDNA检测算法如何针对不同临床环境定制性能。
招募了851例接受根治性治疗的II-III期CRC患者。基于对匹配的肿瘤和种系DNA进行的全外显子测序，选择一个突变靶点用于dPCR分析。术后60天内采集血浆样本（8毫升），对于一部分患者亚组（n = 246），每3-4个月采集一次，最长持续36个月。使用单靶点dPCR检测ctDNA。
术后和连续ctDNA检测均对复发具有预后价值[风险比（HR）= 11.3，95%置信区间（CI）7.8-16.4，P < 0.001；HR = 30.7，95% CI 20.2-46.7，P < 0.001]，在复发患者样本采集结束时，ctDNA累积检测率为87%。ctDNA增长率对生存具有预后价值（HR = 2.6，95% CI 1.5-4.4，P = 0.001）。在复发患者中，术后ctDNA检测对于肺转移（检测到4/21）和腹膜转移（检测到2/10）具有挑战性。通过修改判定样本ctDNA阳性的临界值，我们能够针对不同临床情况调整检测的敏感性和特异性。
来自851例II-III期CRC患者的结果表明，我们的个性化dPCR方法能有效检测术后MRD，并有望用于连续ctDNA检测以进行复发监测。调整敏感性和特异性的能力显示出针对特定临床环境定制ctDNA检测算法的令人兴奋的潜力。
