{"entity":{"id":"idea-crc-ctdna-de-escalation-beyond-stage-ii","kind":"idea","name":"Take ctDNA-guided de-escalation beyond stage II, and stop escalating on a positive result until a trial says it helps","aka":[],"tldr":"A blood test after surgery already lets stage II colon cancer patients skip chemotherapy safely. The same test in stage III would spare far more people, and the unproven half, giving more chemotherapy to those who test positive, has so far changed nothing.","summary":"DYNAMIC randomised 455 patients with stage II colon cancer and cut adjuvant chemotherapy use from 28 to 15 percent with two-year recurrence-free survival of 93.5 against 92.4 percent, non-inferior against a margin of 8.5 percentage points. GALAXY, in 1,039 patients across stages II to IV, found a hazard ratio of 10.0 for recurrence with a positive test four weeks after surgery and showed adjuvant chemotherapy benefit concentrated in the positives (hazard ratio 6.59).\n\nBoth halves of the strategy are unfinished. De-escalation is proven only in stage II, where QUASAR put the absolute survival benefit of chemotherapy at 3.6 percent to begin with; the far larger prize is the stage III population where six months of oxaliplatin is routine and 60 to 70 percent of patients are cured by surgery alone. Escalation has no positive trial at all: the ALTAIR arm of CIRCULATE-Japan, which added trifluridine-tipiracil for ctDNA-positive patients, did not improve outcomes, and this idea takes that as evidence that a more intensive version of the same drug class is the wrong response to a positive test.","asOf":"2026-09-24","links":[{"label":"Tie et al.: DYNAMIC (N Engl J Med 2022)","url":"https://europepmc.org/article/MED/35657320"},{"label":"Kotani et al.: GALAXY (Nat Med 2023)","url":"https://europepmc.org/article/MED/36646802"},{"label":"ClinicalTrials.gov NCT05174169","url":"https://clinicaltrials.gov/study/NCT05174169"},{"label":"ClinicalTrials.gov NCT04120701","url":"https://clinicaltrials.gov/study/NCT04120701"}],"tags":["colorectal-evidence"],"related":["colorectal-roadmap","ctdna-tests","idea-ctdna-guided-adjuvant-crc"],"cancers":["colorectal","colon-cancer"],"sections":["diagnostics","chemotherapy"],"technologies":["mrd-testing","liquid-biopsy","signatera","ngs"],"targets":[],"drugs":["folfox","capox","capecitabine"],"companies":["natera","guardant-health"],"institutions":[],"pathways":[],"terms":["ctdna","mrd","neoadjuvant-adjuvant"],"trials":["dynamic","circulate-japan"],"people":[],"bottlenecks":["b-dormancy-mrd","b-toxicity-qol","b-biomarker-validation"],"keyPapers":["paper-tie-dynamic-ctdna-guided-adjuvant-stage-ii-colon-nejm-2022","paper-kotani-galaxy-molecular-residual-disease-nat-med-2023","paper-tie-ctdna-minimal-residual-disease-stage-ii-colon-sci-transl-med-2016","paper-idea-duration-adjuvant-stage-iii-colon-nejm-2018"],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"In stage III colon cancer, a ctDNA-negative result at four to seven weeks after surgery identifies a group in whom three months of a fluoropyrimidine alone is non-inferior to six months of oxaliplatin-based chemotherapy for three-year disease-free survival, while a positive result identifies a group whose outcome is unchanged by intensifying the same cytotoxic backbone and who should instead be randomised to a mechanistically different agent.","rationale":"The prognostic separation is an order of magnitude, larger than any clinicopathological factor; the de-escalation half has already survived a randomised test in stage II; and the failure of cytotoxic escalation in ALTAIR argues that the positive group needs a different class of drug rather than more of the same.","test":"CIRCULATE-US (NRG-GI008), the French CIRCULATE and DYNAMIC-III readouts, with a pre-registered pooled individual patient analysis across stage III; for the positive group, a separate randomisation to a biology-matched agent rather than to intensified chemotherapy, with three-year disease-free survival as the primary endpoint and chemotherapy exposure and persistent neuropathy as co-primary harms.","maturity":"being-tested-at-scale","actor":"clinic","cost":"large","horizonYears":5},"route":"/ideas/idea-crc-ctdna-de-escalation-beyond-stage-ii/","neighbours":{"roadmap":[{"id":"colorectal-roadmap","kind":"roadmap","name":"Colorectal cancer roadmap: from the adenoma-carcinoma sequence and the first screening trials to total mesorectal excision, oxaliplatin, RAS testing, immunotherapy for mismatch repair-deficient disease, ctDNA-guided treatment and organ preservation","route":"/roadmaps/colorectal-roadmap/"},{"id":"ctdna-tests","kind":"roadmap","name":"ctDNA tests roadmap: from a curiosity in plasma to blood tests that decide treatment","route":"/roadmaps/ctdna-tests/"}],"idea":[{"id":"idea-ctdna-guided-adjuvant-crc","kind":"idea","name":"ctDNA-guided adjuvant therapy as the default in stage II-III colon cancer","route":"/ideas/idea-ctdna-guided-adjuvant-crc/"}],"cancer":[{"id":"colon-cancer","kind":"cancer","name":"Colon cancer (adenocarcinoma of the colon)","route":"/cancers/colon-cancer/"},{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"}],"section":[{"id":"chemotherapy","kind":"section","name":"Chemotherapy","route":"/fronts/chemotherapy/"},{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"}],"technology":[{"id":"liquid-biopsy","kind":"technology","name":"Liquid biopsy (ctDNA)","route":"/technologies/liquid-biopsy/"},{"id":"mrd-testing","kind":"technology","name":"MRD / molecular residual disease testing","route":"/technologies/mrd-testing/"}],"drug":[{"id":"capecitabine","kind":"drug","name":"Capecitabine","route":"/drugs/capecitabine/"},{"id":"capox","kind":"drug","name":"CAPOX (capecitabine, oxaliplatin)","route":"/drugs/capox/"},{"id":"folfox","kind":"drug","name":"FOLFOX (5-FU, leucovorin, oxaliplatin)","route":"/drugs/folfox/"},{"id":"signatera","kind":"drug","name":"Signatera","route":"/drugs/signatera/"}],"term":[{"id":"ctdna","kind":"term","name":"Circulating tumour DNA (ctDNA)","route":"/terms/ctdna/"},{"id":"mrd","kind":"term","name":"Minimal / molecular residual disease (MRD)","route":"/terms/mrd/"},{"id":"neoadjuvant-adjuvant","kind":"term","name":"Neoadjuvant / adjuvant / perioperative","route":"/terms/neoadjuvant-adjuvant/"},{"id":"ngs","kind":"term","name":"Next-generation sequencing (NGS)","route":"/terms/ngs/"}],"company":[{"id":"guardant-health","kind":"company","name":"Guardant Health","route":"/companies/guardant-health/"},{"id":"natera","kind":"company","name":"Natera","route":"/companies/natera/"}],"trial":[{"id":"circulate-japan","kind":"trial","name":"CIRCULATE-Japan (GALAXY / VEGA / ALTAIR)","route":"/trials/circulate-japan/"},{"id":"dynamic","kind":"trial","name":"DYNAMIC","route":"/trials/dynamic/"}],"bottleneck":[{"id":"b-biomarker-validation","kind":"bottleneck","name":"Biomarkers are not validated or standardised","route":"/bottlenecks/b-biomarker-validation/"},{"id":"b-dormancy-mrd","kind":"bottleneck","name":"Dormant cells and minimal residual disease","route":"/bottlenecks/b-dormancy-mrd/"},{"id":"b-toxicity-qol","kind":"bottleneck","name":"Toxicity and quality of life are undervalued","route":"/bottlenecks/b-toxicity-qol/"}],"paper":[{"id":"paper-tie-ctdna-minimal-residual-disease-stage-ii-colon-sci-transl-med-2016","kind":"paper","name":"Circulating tumor DNA analysis detects minimal residual disease and predicts recurrence in patients with stage II colon cancer","route":"/key-papers/paper-tie-ctdna-minimal-residual-disease-stage-ii-colon-sci-transl-med-2016/"},{"id":"paper-tie-dynamic-ctdna-guided-adjuvant-stage-ii-colon-nejm-2022","kind":"paper","name":"Circulating tumor DNA analysis guiding adjuvant therapy in stage II colon cancer (DYNAMIC)","route":"/key-papers/paper-tie-dynamic-ctdna-guided-adjuvant-stage-ii-colon-nejm-2022/"},{"id":"paper-idea-duration-adjuvant-stage-iii-colon-nejm-2018","kind":"paper","name":"Duration of adjuvant chemotherapy for stage III colon cancer (the IDEA collaboration)","route":"/key-papers/paper-idea-duration-adjuvant-stage-iii-colon-nejm-2018/"},{"id":"paper-kotani-galaxy-molecular-residual-disease-nat-med-2023","kind":"paper","name":"Molecular residual disease and efficacy of adjuvant chemotherapy in patients with colorectal cancer (GALAXY, CIRCULATE-Japan)","route":"/key-papers/paper-kotani-galaxy-molecular-residual-disease-nat-med-2023/"}]}}