The Galleri test (GRAIL Galleri) is a multi-cancer early detection blood test that analyzes cell-free DNA methylation patterns to screen for more than 50 types of cancer in asymptomatic adults, typically aged 50 and older[4][3][1]. It uses artificial intelligence to identify cancer-associated DNA changes and can often predict the likely tissue of origin[4][1].

Key benefits:

  • Broad cancer detection: Screens for over 50 cancer types, including many not covered by standard screening tests[4][1].
  • Early detection: Can identify cancers at earlier stages, potentially before symptoms develop, which may improve outcomes[4][2].
  • High specificity: The test has a reported specificity of 99.5%, meaning a low rate of false positives[4].
  • Tissue of origin prediction: Correctly predicts the tissue of origin in about 89% of true-positive cases[4].
  • Convenient blood test: Non-invasive and can be performed alongside routine blood work[4][1].

Limitations and context:

  • Sensitivity varies by cancer type and stage: Overall sensitivity is 51.5%, increasing with cancer stage (e.g., 16.8% for stage I, 90.1% for stage IV)[4].
  • Not FDA-approved: The test is not currently approved by the U.S. Food and Drug Administration and is not intended to replace existing cancer screening guidelines[4].
  • Clinical utility under investigation: Large trials (e.g., NHS-Galleri) are ongoing to determine its impact on reducing late-stage cancer incidence and mortality[2].

In summary, the Galleri test offers a promising approach for broad, early cancer detection using a single blood sample, with high specificity and the ability to identify the tissue of origin, but its role in routine clinical practice is still being evaluated[4][2][1].

Sources:

  1. Emerging Multi-Cancer Early Detection Technologies.
  2. Cell-Free DNA-Based Multi-Cancer Early Detection Test in an Asymptomatic Screening Population (NHS-Galleri): Design of a Pragmatic, Prospective Randomised Controlled Trial – PubMed.
  3. Evaluating multi-cancer early detection tests: an argument for the outcome of recurrence-updated stage.
  4. Galleri Test for the Detection of Cancer.
  5. Multicancer Early Detection Tests: A State‐of‐the‐Art Review for Otolaryngologists.

GALLERI Scientific Slide Presentation