synthesis Across the trial spine, two complementary evidence types address ctDNA-guided adjuvant modulation after curative-intent resection. DYNAMIC (stage II colon cancer RCT) directly licenses de-escalation when ctDNA is negative in the post-resection MRD window: fewer patients received adjuvant chemotherapy (15% vs 28%) without compromising 2-year RFS under a prespecified noninferiority design. GALAXY (observational CIRCULATE-Japan registry; stage II–III colon and stage IV CRC) does not randomize treatment but shows that ctDNA clearance dynamics under adjuvant chemotherapy stratify outcomes sharply—sustained versus transient clearance separates 24-month DFS/OS—supporting the biological premise that ctDNA negativity/clearance marks a lower-risk subgroup where intensified or prolonged therapy may be unnecessary, while failure to clear marks escalation need. Joint reading for the sub-topic: DYNAMIC supplies the stage II–specific causal policy test for withholding chemotherapy when MRD-negative; GALAXY supplies mechanistic/prognostic reinforcement and escalation logic when MRD persists or clears only transiently, with explicit population caveats because GALAXY is not stage II–restricted. Neither node alone answers both de-escalation licensure and escalation rationale; together they frame ctDNA-guided adjuvant decisions as bidirectional (omit when negative/sustainedly clear; treat when positive or poorly clearing) pending further stage II–restricted observational/randomized readouts (e.g., BESPOKE-CRC, ongoing RCTs).
nod_d3956d56-a89d-4a34-8b1c-bf32ea235890
Provenance
- Proposed by idn_f3a0c317-0b3f-4ef4-aac0-3217bbc9f5ad
- Created 2026-06-06T21:15:39.527Z
- Status: active