# A 28-day national pathway for people with a positive multi-cancer blood test

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

## TL;DR

A positive blood test with no known tumour is frightening and hard to manage. A standard imaging cascade with a time limit, and a registry of what was found, would make these tests usable.

## Summary

PATHFINDER showed diagnostic resolution sometimes took months and repeated procedures. Propose a protocolised pathway: tissue-of-origin-directed imaging first, PET-CT second, FAPI PET or whole-body MRI third, explicit stopping rules for unresolved positives (repeat test at six months), and a mandatory registry of investigations, complications, and outcomes per positive.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: A protocolised pathway achieves diagnostic resolution within 28 days in at least 80% of positives with two or fewer imaging procedures on average, and halves invasive procedures per false positive relative to unstructured care.
- Rationale: NHS Rapid Diagnostic Centres already do this for non-specific symptoms; the MCED positive is a new referral reason for the same machinery.
- Proposed test: Compare structured versus usual-care resolution in the NHS-Galleri implementation phase.
- Maturity: early-clinical
- Actor: clinic

## 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

- ideas: [FAPI PET as the workup for MCED positives](https://onco.cc/ideas/idea-mced-plus-fapi/)
- fronts: [Early Detection & Screening](https://onco.cc/fronts/early-detection/)
- technologies: [FAPI PET](https://onco.cc/technologies/fapi-pet/), [Multi-cancer early detection (MCED)](https://onco.cc/technologies/mced/), [PET/CT](https://onco.cc/technologies/pet-ct/), [Whole-body MRI](https://onco.cc/technologies/whole-body-mri/)
- terms: [Positive predictive value (PPV)](https://onco.cc/terms/ppv/)
- bottlenecks: [Overdiagnosis and false alarms](https://onco.cc/bottlenecks/b-overdiagnosis/), [The hardest cancers are found late](https://onco.cc/bottlenecks/b-early-detection/)
- key papers: [Early detection of cancer](https://onco.cc/key-papers/paper-crosby-science/), [PATHFINDER: the first prospective test of a multi-cancer blood test in people without symptoms](https://onco.cc/key-papers/paper-pathfinder-lancet-2023/)
- roadmaps: [ctDNA tests roadmap: from a curiosity in plasma to blood tests that decide treatment](https://onco.cc/roadmaps/ctdna-tests/)

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