Methylation is a promising approach
In 2019, GRAIL announced its proprietary methylation technology, which comprises detection of DNA shed into the blood and machine learning, to recognize a “fingerprint” for cancer. Our technology does this by analyzing more than one million methylation sites on DNA fragments in the blood.
When comparing samples from patients both with and without cancer, GRAIL’s technology was able to identify a cancer signal and predict the cancer signal origin with a high degree of accuracy (88%).1*
Cells in our bodies, including cancer cells, release DNA fragments into our blood. These DNA fragments have methyl molecules attached to them in methylation patterns to turn genes (sections of the DNA) on and off. The patterns are different between cancer cells and healthy cells (and can be used as a cancer “fingerprint”), and also between cells from different organs. These methylation patterns predict the cancer signal origin.
Although the cancer “fingerprint” is shared by all cancers, the rate at which different cells in the body shed DNA is inherently different (more aggressive cancers shed more DNA), and the rate DNA is shed also varies by the stage (or amount) of the cancer.
Since the Galleri® test detects DNA shed into the blood by developing cancers, it screens for many of the deadliest cancers that don’t have recommended screening today. The Galleri test does not detect a signal for all cancers and not all cancers can be detected in the blood. False positive and false negative results do occur. Galleri should be used in addition to healthcare provider recommended screening tests.
Following extensive clinical research, GRAIL believes methylation is the most promising approach to detecting a cancer signal and identifying the tissue type or organ associated with the cancer signal.
The Galleri test is recommended for use in adults with an elevated risk for cancer, such as those aged 50 or older. The Galleri test does not detect all cancers and should be used in addition to routine cancer screening tests recommended by a healthcare provider. Galleri is intended to detect cancer signals and predict where in the body the cancer signal is located. Use of Galleri is not recommended in individuals who are pregnant, 21 years old or younger, or undergoing active cancer treatment.
Results should be interpreted by a healthcare provider in the context of medical history, clinical signs and symptoms. A test result of “Cancer Signal Not Detected” does not rule out cancer. A test result of “Cancer Signal Detected” requires confirmatory diagnostic evaluation by medically established procedures (e.g. imaging) to confirm cancer.
If cancer is not confirmed with further testing, it could mean that cancer is not present or testing was insufficient to detect cancer, including due to the cancer being located in a different part of the body. False-positive (a cancer signal detected when cancer is not present) and false-negative (a cancer signal not detected when cancer is present) test results do occur. Rx only.
GRAIL’s clinical laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and accredited by the College of American Pathologists (CAP). The Galleri test was developed, and its performance characteristics were determined by GRAIL. The Galleri test has not been cleared or approved by the U.S. Food and Drug Administration. GRAIL’s clinical laboratory is regulated under CLIA to perform high-complexity testing. The Galleri test is intended for clinical purposes.
References
1. Schrag D, Beer TM, McDonnell CH, et al. Blood based tests for multi-cancer early detection (PATHFINDER): a prospective cohort study. Lancet. 2023;402:1251-1260. doi: 10.1016/S0140-6736(23)01700-2.
*In the PATHFINDER study, Cancer Signal Origin (CSO) prediction accuracy was 88% for participants with a cancer diagnosis after a “Cancer Signal Detected” test result. This is the proportion of first or second origins correctly predicted among true positive participants.