# Multi-cancer blood test as the first step for patients with non-specific symptoms

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

## TL;DR

People with vague symptoms such as fatigue and weight loss are worked up with repeated scans. A multi-cancer blood test as the first step in Rapid Diagnostic Centres could point to which organ to examine first, or safely reassure; SYMPLIFY showed the Galleri test has high specificity in symptomatic patients.

## Summary

People with vague symptoms such as fatigue and weight loss undergo repeated scans, so this idea makes a multi-cancer blood test the first step in Rapid Diagnostic Centre pathways, pointing to which organ to examine first or safely reassuring. SYMPLIFY from Oxford showed that Galleri, the GRAIL MCED, had high specificity and useful tissue-of-origin accuracy in symptomatic patients, and because cancer prevalence in symptomatic referrals is far higher than in screening, positive predictive value is better. An RCT would compare MCED-directed with standard work-up on time to diagnosis, imaging use and stage. The test is a 6,000-patient trial across ten NHS Rapid Diagnostic Centres. At early-clinical maturity it addresses the bottleneck The hardest cancers are found late.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: MCED-first triage shortens median time to diagnosis by at least seven days and cuts imaging procedures per cancer diagnosed by at least 25% without missing cancers.
- Rationale: Cancer prevalence in symptomatic referrals (about 7%) is ten times that of screening, so positive predictive value is far better and overdiagnosis less of a concern.
- Proposed test: Run a 6,000-patient RCT across ten NHS Rapid Diagnostic Centres.
- 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

- fronts: [Diagnostics & Biomarkers](https://onco.cc/fronts/diagnostics/), [Early Detection & Screening](https://onco.cc/fronts/early-detection/)
- technologies: [Multi-cancer early detection (MCED)](https://onco.cc/technologies/mced/)
- drugs: [Galleri](https://onco.cc/drugs/galleri/)
- companies: [GRAIL](https://onco.cc/companies/grail/)
- terms: [Positive predictive value (PPV)](https://onco.cc/terms/ppv/)
- bottlenecks: [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/)

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