Purpose: No study has investigated the precise perioperative dynamic changes in circulating tumor DNA (ctDNA) in any patients with early-stage cancer. This study (DYNAMIC) investigated perioperative dynamic changes in ctDNA and determined the appropriate detection time of ctDNA-based surveillance for surgical patients with lung cancer.Experimental Design: Consecutive patients who underwent curative-intent lung resections were enrolled prospectively (NCT02965391). Plasma samples were obtained at multiple prespecified time points including before surgery (time A), during surgery after tumor resection (time B-time D), and after surgery (time P1-time P3). Next-generation sequencing-based detection platform was performed to calculate the plasma mutation allele frequency. The primary endpoint was ctDNA half-life after radical tumor resection.
Results: Thirty-six patients showed detectable mutations in time A. The plasma ctDNA concentration showed a rapid decreasing trend after radical tumor resection, with the average mutant allele fraction at times A, B, C, and D being 2.72%, 2.11%, 1.14%, and 0.17%, respectively. The median ctDNA half-life was 35.0 minutes. Patients with minimal residual disease (MRD) detection had a significant slower ctDNA half-life than those with negative MRD (103.2 minutes vs. 29.7 minutes, P = 0.001). The recurrence-free survival of patients with detectable and undetectable ctDNA concentrations at time P1 was 528 days and 543 days, respectively (P = 0.657), whereas at time P2 was 278 days and 637 days, respectively (P = 0.002).
Conclusions: ctDNA decays rapidly after radical tumor resection. The ctDNA detection on the third day after R0 resection can be used as the baseline value for postoperative lung cancer surveillance.
©2019 American Association for Cancer Research.