ASCO-GI 2020 – Blood test may detect gastrointestinal cancers


  • Deepa Koli
  • Univadis
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Takeaway

  • A single noninvasive blood test shows high sensitivity, specificity, predicted tissue of origin in the detection of multiple gastrointestinal (GI) cancers.

Why this matters

  • A single blood test can be a practical and convenient method of detecting cancers and may facilitate diagnostic workups.

Study design

  • Prospective, multi-center, observational, case-control Circulating Cell-free Genome Atlas study of 15,254 participants with and without cancer.
  • An assay was developed using targeted methylation sequencing of plasma cell-free DNA.
  • Funding: GRAIL, Inc.

Key results

  • The assay had a specificity of 99.8% in the training set and 99.3% in the validation set.
  • The sensitivity and accuracy of the predicted tissue of origin across all GI cancers was 82% and 92%, respectively:
    • Upper GI tract: 85% and 87%, respectively.
    • Pancreas/gallbladder/extrahepatic bile duct: 82% and 92%, respectively.
    • Liver/intrahepatic bile duct: 86% and 78%, respectively.
    • Colon/rectum: 79% and 98%, respectively.

Limitations

  • Observational design.

Expert commentary

Lead Investigator Wolpin BM, MD, MPH, noted: “To pursue early detection at a population scale while minimizing harm and cost, several features are important, including a low false-positive rate, a high detection rate, the ability to localize the site of origin of the malignancy, and limiting overdiagnosis”.