# The PATHFINDER Study: Assessment of the Implementation of an Investigational Multi-Cancer Early Detection Test into Clinical Practice

Source: https://onco.cc/key-papers/paper-pathfinder-design-cancers-2021/  
OnCo record `paper-pathfinder-design-cancers-2021` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The published plan for PATHFINDER, the first study to give Galleri results back to people without symptoms, set out what it would measure and what it expected to find.

## Summary

Design paper for PATHFINDER (NCT04241796): about 6,200 participants aged 50 or older with or without additional cancer risk factors would have a targeted methylation cell-free DNA test, with signal-detected participants evaluated at their physician's discretion. The primary objective was the number and types of diagnostic tests needed for diagnostic resolution. From microsimulations the authors expected a median of 106 signal-detected results, 52 cancers and a positive predictive value of 49% (95% CI 39 to 58).

## Fields

- Kind: Key paper
- Last checked: 2026-10-29
- Journal: Cancers
- Year: 2021
- DOI: 10.3390/cancers13143501
- Authors: Nadauld LD, McDonnell CH, Beer TM, et al.
- Findings: Expected 106 signal-detected results, 52 cancers and positive predictive value 49% by microsimulation.; Primary objective: the diagnostic tests needed to resolve a positive result.
- What it means: Set beside the result (35 cancers among 92 positives, positive predictive value 38%), it shows the test found fewer cancers than its makers had modelled.
- Caveats: Projections, not results.; Sponsored by GRAIL.

## Sources

- Cancers 2021: PATHFINDER design: https://doi.org/10.3390/cancers13143501
- PubMed: https://pubmed.ncbi.nlm.nih.gov/34298717/

## Connected records

- key papers: [PATHFINDER: the first prospective test of a multi-cancer blood test in people without symptoms](https://onco.cc/key-papers/paper-pathfinder-lancet-2023/)
- fronts: [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/)
- trials: [PATHFINDER (first prospective study of the Galleri test)](https://onco.cc/trials/pathfinder/)
- journals: [Cancers](https://onco.cc/journals/cancers-mdpi/)

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