# Registry-based randomised MCED trial: a million people, no study visits

Source: https://onco.cc/ideas/idea-prev-mced-registry-randomised/  
OnCo record `idea-prev-mced-registry-randomised` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Randomise people through the national health system, post the blood kit, and read cancer deaths off the registry. That is ten times cheaper per participant than a classic trial.

## Summary

Swedish registry-based RCTs (TASTE, DETO2X) showed pragmatic randomisation at national scale at a fraction of usual cost. Propose an MCED trial that randomises through screening call/recall, draws blood at existing phlebotomy or mobile units, and uses cancer registry and death-certificate linkage for endpoints, with no in-person study visits.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: A registry-based RCT of at least one million adults aged 50-79 can detect a 15% relative reduction in cancer mortality within eight years at under $50 per participant-year.
- Rationale: MCED effects on all-cancer mortality will be modest and need very large samples; only registry-linked pragmatic designs make that affordable.
- Proposed test: Feasibility pilot in a Nordic country or NHS region (100,000 invitations, mailed kits; uptake and linkage completeness as endpoints), then scale.
- Maturity: speculative
- Actor: research

## Sources

- Bottleneck evidence (The hardest cancers are found late): Crosby et al., Early detection of cancer (Science 2022): https://doi.org/10.1126/science.aay9040

## Connected records

- fronts: [Early Detection & Screening](https://onco.cc/fronts/early-detection/)
- technologies: [Multi-cancer early detection (MCED)](https://onco.cc/technologies/mced/)
- institutions: [Karolinska University Hospital](https://onco.cc/institutions/karolinska/)
- terms: [Stage shift](https://onco.cc/terms/stage-shift/)
- bottlenecks: [The hardest cancers are found late](https://onco.cc/bottlenecks/b-early-detection/), [Trials enrol too few, too slowly](https://onco.cc/bottlenecks/b-trial-enrolment/)
- key papers: [Early detection of cancer](https://onco.cc/key-papers/paper-crosby-science/), [NHS-Galleri: design of the largest randomised trial of a multi-cancer blood test](https://onco.cc/key-papers/paper-nhs-galleri-design-cancers-2022/)
- trials: [Vanguard Study (NCI Cancer Screening Research Network)](https://onco.cc/trials/vanguard-study/)

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