An investigational blood test developed by startup Grail has high sensitivity and specificity across a range of gastrointestinal (GI) cancer types, though more validating data are needed to support use, according to an analysis set to be presented on January 23.
Data from Grail's Circulating Cell-free Genome Atlas (CCGA) study are due to be presented at the American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium, slated for January 23-25 in San Francisco. The analysis was one of a trio of abstracts selected by ASCO as highlights of the meeting.
The presentation focuses on how Grail's liquid biopsy approach fares in gastrointestinal cancers, following reports in 2019 for the test across 20 tumor types in the CCGA study, which includes some 15,000 participants with and without cancer at the time of enrollment.
The test detects methylation patterns associated with cancer in cell-free DNA. The study to be presented at the meeting assesses its value in the following tumor types:
- Esophageal/stomach cancers (n = 69)
- Pancreas/gallbladder/extrahepatic bile duct (n = 95)
- Liver/intrahepatic bile duct (n = 29)
- Colon/rectum (n = 121)
Sensitivity for cancer detection was 82% in a training set and 81% for a validation set, with a specificity of more than 99%, the researchers found.
"Many of the cancer types that this test detects don't currently have screening tests that allow earlier cancer detection before the cancers cause symptoms," lead investigator Dr. Brian Wolpin, director of the Gastrointestinal Cancer Treatment Center at the Dana-Farber Cancer Institute, said in a statement from ASCO.
|CCGA: Zooming in on gastrointestinal cancers|
|Sensitivity % (n)||Predicted tissue of origin accuracy % (n)|
|GI cancer type||All||Stage I-III||Stage IV||All||Stage I-III||Stage IV|
|Upper GI||85%||75% (30/40)||100% (27/27)||87%||86% (24/28)||89% (24/27)|
extrahepatic bile duct
|82%||69% (34/49)||96% (44/46)||92%||94% (31/33)||91% (40/44)|
|Liver/intrahepatic bile duct||86%||79% (15/19)||100% (10/10)||78%||85% (11/13)||70% (7/10)|
|Colon/rectum||79%||70% (53/76)||93% (42/45)||98%||96% (50/52)||100% (42/42)|
|All GI cancers||82%||72%||96%||92%||92%||92%|
Based in Menlo Park, CA, Grail is backed by many high-profile investors including Illumina, Jeff Bezos, Bill Gates, Bristol-Myers Squibb, and Johnson & Johnson. The company said it has raised more than $1.5 billion since 2016.
In addition to the CCGA study, Grail's blood testing for early cancer detection is being examined in two other trials. The fully enrolled STRIVE study is evaluating blood testing prospectively in 100,000 women undergoing screening mammography. Meanwhile, the U.K.-based SUMMIT study is testing liquid biopsy in 50,000 men and women between the ages of 50 and 77 who have not been diagnosed with cancer. A key focus of SUMMIT will be on detection in people at risk of cancer due to smoking.