{"entity":{"id":"continuous-ctdna-monitoring","kind":"technology","name":"Continuous and near-continuous ctDNA monitoring","aka":[],"tldr":"Instead of testing blood every three months, sampling constantly, so a relapse is caught the week it starts.","summary":"MRD testing already detects relapse months before imaging, but sampling is episodic. Work on implantable and wearable sampling, microneedle interstitial-fluid collection, and at-home dried blood spots aims to shorten the interval, while urine and saliva ctDNA reduce the burden of venepuncture. Nothing in this class was validated for clinical use by 2026, and the question of what to do with an earlier signal is still open.","status":"concept","asOf":"2026-09-08","links":[{"label":"ClinicalTrials.gov: serial ctDNA monitoring","url":"https://clinicaltrials.gov/search?term=serial%20ctDNA%20monitoring"}],"tags":["frontier","promising"],"related":[],"cancers":[],"sections":["diagnostics"],"technologies":["mrd-testing","liquid-biopsy","fragmentomics"],"targets":[],"drugs":[],"companies":["natera","guardant-health","foresight-diagnostics"],"institutions":[],"pathways":[],"terms":["ctdna","mrd"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"principle":"Frequent low-volume sampling of blood or interstitial fluid, with error-suppressed sequencing or targeted PCR, turns a periodic test into a trend line.","strengths":["Earlier detection of relapse and of resistance","A trend beats a single value for treatment decisions","Fewer clinic visits"],"limitations":["No validated device","Assay sensitivity limited by cfDNA quantity in small samples","Lead time without a proven intervention causes harm as well as good"]},"route":"/technologies/continuous-ctdna-monitoring/","neighbours":{"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"}],"technology":[{"id":"fragmentomics","kind":"technology","name":"cfDNA fragmentomics","route":"/technologies/fragmentomics/"},{"id":"clonal-evolution-models","kind":"technology","name":"Clonal evolution and branching models","route":"/technologies/clonal-evolution-models/"},{"id":"liquid-biopsy","kind":"technology","name":"Liquid biopsy (ctDNA)","route":"/technologies/liquid-biopsy/"},{"id":"metastasis-seeding-models","kind":"technology","name":"Metastatic seeding and dormancy models","route":"/technologies/metastasis-seeding-models/"},{"id":"mrd-testing","kind":"technology","name":"MRD / molecular residual disease testing","route":"/technologies/mrd-testing/"},{"id":"mrd-kinetics-models","kind":"technology","name":"Residual disease kinetics (BCR-ABL halving and ctDNA slopes)","route":"/technologies/mrd-kinetics-models/"}],"company":[{"id":"foresight-diagnostics","kind":"company","name":"Foresight Diagnostics","route":"/companies/foresight-diagnostics/"},{"id":"guardant-health","kind":"company","name":"Guardant Health","route":"/companies/guardant-health/"},{"id":"natera","kind":"company","name":"Natera","route":"/companies/natera/"}],"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/"}],"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"}],"paper":[{"id":"paper-reinert-ctdna-ultradeep-sequencing-colorectal-jama-oncol-2019","kind":"paper","name":"Analysis of plasma cell-free DNA by ultradeep sequencing in patients with stages I to III colorectal cancer","route":"/key-papers/paper-reinert-ctdna-ultradeep-sequencing-colorectal-jama-oncol-2019/"},{"id":"paper-oxnard-osimertinib-resistance-mechanisms-jama-oncol-2018","kind":"paper","name":"Assessment of resistance mechanisms and clinical implications in patients with EGFR T790M-positive lung cancer and acquired resistance to osimertinib","route":"/key-papers/paper-oxnard-osimertinib-resistance-mechanisms-jama-oncol-2018/"},{"id":"paper-henriksen-ctdna-stage-iii-colorectal-improve-it-ccr-2022","kind":"paper","name":"Circulating tumor DNA in stage III colorectal cancer, beyond minimal residual disease detection, toward assessment of adjuvant therapy efficacy and clinical behavior of recurrences","route":"/key-papers/paper-henriksen-ctdna-stage-iii-colorectal-improve-it-ccr-2022/"},{"id":"paper-galaxy-signatera-nat-med-2023","kind":"paper","name":"GALAXY: tumour DNA in blood four weeks after bowel cancer surgery predicts relapse tenfold","route":"/key-papers/paper-galaxy-signatera-nat-med-2023/"}],"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/"},{"id":"diagnostics-roadmap","kind":"roadmap","name":"Diagnostics roadmap: stains → gene panels → blood tests that decide treatment","route":"/roadmaps/diagnostics-roadmap/"},{"id":"cure-paths","kind":"roadmap","name":"Paths to cures: interception, eradication, control","route":"/roadmaps/cure-paths/"},{"id":"frontier-2035","kind":"roadmap","name":"Radical oncology: what could change the war by 2035","route":"/roadmaps/frontier-2035/"}],"trial":[{"id":"mermaid-2","kind":"trial","name":"MERMAID-2","route":"/trials/mermaid-2/"}],"pathway":[{"id":"drug-tolerant-persisters","kind":"pathway","name":"Drug-tolerant persister cells","route":"/pathways/drug-tolerant-persisters/"},{"id":"intravasation-ctc-survival","kind":"pathway","name":"Intravasation & circulating tumour cells","route":"/pathways/intravasation-ctc-survival/"}]}}