Fig. 6: Patients turning ctDNA positive after MRD negativity or transient ctDNA clearance.
From: ctDNA-based molecular residual disease and survival in resectable colorectal cancer
a,b, Kaplan–Meier estimates for DFS (a) and OS (b) stratified by ctDNA clearance patterns (no clearance versus transient clearance versus sustained clearance) in MRD-positive patients receiving ACT. *Based on Firth’s penalized maximum likelihood; P value from log-rank test. P = 1.78 × 10–12 (a, transient clearance); P = 3.97 × 10–26 (a, no clearance); P = 3.72 × 10–9 (b, no clearance). Two-sided chi-square test for bar plots: P = 6.69 × 10–28 (a); P = 3.11 × 10–6 (b). c, Among patients with transient clearance who recurred (n = 50), the cumulative incidence plot demonstrates a timeline of patients turning back ctDNA positive (time from surgery). d, Among MRD-negative patients who had molecular recurrence before radiological recurrence (n = 165), the cumulative incidence plot demonstrated a timeline of when the patients turned ctDNA positive. e, Kaplan–Meier estimates for OS stratified by ctDNA MRD status and molecular recurrence during the surveillance window (all-time ctDNA negative versus MRD negative with molecular recurrence versus MRD positive). P = 7.09 × 10−11 (MRD positive). Two-sided chi-square test for bar plot: P = 2.63 × 10–31. f, Kaplan–Meier estimates for OS stratified by timing of molecular recurrence after surgery. HRs and 95% CIs were calculated using the Cox proportional hazard model (a,e) or Cox regression with Firth’s penalized likelihood hazard model (b,f). P values were calculated using the two-sided log-rank test. These analyses were landmarked at the MRD timepoint date and were performed using R software version 4.4.0. Median DFS and OS and percentage DFS and OS at 24 months were estimated from the landmark timepoint.
