Henriksen Tenna V, Demuth Christina, Frydendahl Amanda, Nors Jesper, Nesic Marijana, Rasmussen Mads H, Larsen Ole H, Jaensch Claudia, Løve Uffe S, Andersen Per V, Kolbro Thomas, Thorlacius-Ussing Ole, Monti Alessio, Kildsig Jeppe, Bondeven Peter, Schlesinger Nis H, Iversen Lene H, Gotschalck Kåre A, Andersen Claus L
Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark.
Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
Clin Cancer Res. 2025 May 1;31(9):1676-1685. doi: 10.1158/1078-0432.CCR-24-3200.
Multiple clinical trials are investigating ctDNA to guide adjuvant chemotherapy (ACT) in colorectal cancer. Timely ACT initiation necessitates early ctDNA testing, but the impact of postoperative cell-free DNA (cfDNA) and ctDNA dynamics remains unclear, particularly with cost-reducing input caps employed in some assays. This study investigates ctDNA detection at day 14 versus day 30, comparing whole-sample analysis with capping the cfDNA input, and evaluates single and dual timepoint assessments for ACT allocation.
From 2019 to 2023, 611 patients with stage I to III colorectal cancer were enrolled. Blood was collected preoperatively and postoperatively on ∼day 14 and ∼day 30. The cfDNA levels were assessed using digital PCR, and ctDNA was assessed using tumor-informed digital PCR or targeted sequencing analyzing all cfDNA from 8 mL of plasma.
Despite elevated cfDNA in 85% of day 14 samples, performance was comparable between the two timepoints (sensitivity, 31% vs. 32% and specificity, both 98%). A 50-ng cfDNA input cap reduced ctDNA detection probability, affecting 78% of day 14 samples and 65% of day 30 samples. At both timepoints, ctDNA detection was prognostic of recurrence (day 14; HR, 9.0, 95% confidence interval, 5.5-14.8 and day 30: HR, 12.5, 95% confidence interval, 7.6-20.4). In 74% of ctDNA-positive recurrence patients, both samples had ctDNA detected. An increase in the ctDNA level from day 14 to day 30 was associated with a shorter time to recurrence (Pearson R = -0.63, P = 0.003). Combining the timepoints would increase sensitivity (36%) and allow earlier ACT start in 80% of patients.
Early ctDNA sampling is feasible and highly prognostic. Supplemental later testing may improve sensitivity while allowing early ACT initiation for most ctDNA-positive patients.
多项临床试验正在研究循环肿瘤DNA（ctDNA）以指导结直肠癌的辅助化疗（ACT）。及时开始ACT需要尽早进行ctDNA检测，但术后游离DNA（cfDNA）和ctDNA动态变化的影响仍不清楚，特别是在一些检测中采用了降低成本的输入上限时。本研究调查了第14天与第30天的ctDNA检测情况，比较了全样本分析与对cfDNA输入进行封顶的情况，并评估了用于ACT分配的单时间点和双时间点评估。
2019年至2023年，纳入了611例I至III期结直肠癌患者。在术前以及术后约第14天和第30天采集血液。使用数字PCR评估cfDNA水平，使用肿瘤知情数字PCR或靶向测序分析8 mL血浆中的所有cfDNA来评估ctDNA。
尽管85%的第14天样本中cfDNA升高，但两个时间点的检测性能相当（敏感性分别为31%对32%，特异性均为98%）。50 ng的cfDNA输入上限降低了ctDNA检测概率，影响了78%的第14天样本和65%的第30天样本。在两个时间点，ctDNA检测均对复发具有预后价值（第14天；风险比[HR]，9.0，95%置信区间，5.5 - 14.8；第30天：HR，12.5，95%置信区间，7.6 - 20.4）。在74%的ctDNA阳性复发患者中，两个样本均检测到ctDNA。从第14天到第30天ctDNA水平升高与复发时间缩短相关（Pearson相关系数R = -0.63，P = 0.003）。结合两个时间点将提高敏感性（36%），并使80%的患者能够更早开始ACT。
早期ctDNA采样是可行的且具有高度预后价值。后期的补充检测可能会提高敏感性，同时让大多数ctDNA阳性患者能够尽早开始ACT。
