ReviewEBioMedicine2026
Common analysis pitfalls in longitudinal ctDNA studies: lead time, sensitivity and immortal time bias.
Review in EBioMedicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
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Authors and funding
8 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Circulating tumour DNA (ctDNA) has emerged as one of the most promising biomarkers in oncology, with potential applications from detection of minimal residual disease (MRD) and diagnosis to prognosis, treatment guidance, and response monitoring. This personal view critically examines recurring methodological and statistical pitfalls in ctDNA studies with longitudinal measurements. We highlight important issues with lead time definition and demonstrate that performance metrics like sensitivity and specificity are inherently time-dependent. Furthermore, we show why immortal time bias arises when classifying patients incorrectly as always positive, based on becoming positive during surveillance in MRD related studies. With a combination of toy data examples, simulations, and re-analysis of published data we provide practice-oriented guidance to support the design, analysis, and reporting of ctDNA trials. This viewpoint paper aims to sensitise the community and raise awareness of pitfalls in longitudinal ctDNA analysis, rather than offer definitive solutions-more evidence is needed first.
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Registered trials
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