
Your guide to Galleri results
The Galleri multi-cancer early detection test screens for a signal shared by multiple cancers through a simple blood draw. In a clinical study, the Galleri test was able to detect more than 50+ types of cancer.1 – 2
Things to remember:
- Galleri is a screening test and does not diagnose cancer. Diagnostic testing is needed to confirm cancer.
- The Galleri test looks for active cancer and does not predict your future genetic risk for cancer.
- The Galleri test does not detect all cancers and not all cancers can be detected in the blood.
- False positives and false negatives can occur.


Have you already taken the Galleri test?
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What results can I expect?
Your results will be available about two weeks after your sample arrives at the GRAIL laboratory.
There are two possible test results: “No Cancer Signal Detected” and “Cancer Signal Detected.” Keep in mind that you will not receive a list of 50+ types of cancer and a result for each one.
*False positive and false negative results do occur.
Did you know?
In order to deliver a test result, the Galleri test looks at over one million DNA methylation sites on cell-free DNA in a blood sample using the latest discoveries in science and DNA sequencing technology.
The majority of people who take the Galleri test will receive a test result of No Cancer Signal Detected. In a clinical study of adults over 50 years of age with an elevated risk of cancer, almost 99% results came back with this result.3
What do the test results mean?
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What does a “Cancer Signal Detected” result mean?
The Galleri test detected a signal associated with cancer.
This result will also include one or two predictions of where in the body the cancer signal may be coming from, called “Cancer Signal Origins.”
In a clinical study, around 4 out of 10 people with this result were diagnosed with cancer after diagnostic testing.4
NEXT STEPS
A Cancer Signal Detected test result is not a cancer diagnosis and requires follow-up diagnostic tests such as imaging or blood tests ordered by your healthcare provider to confirm cancer.
GRAIL also offers patients and providers additional support and resources if needed to help guide next steps.
Other: Anus, Bone and Soft Tissue, Head and Neck, Lymphoid Lineage, Melanocytic Lineage, Myeloid Lineage, Neuroendocrine Cells of Lung or other Organs, Plasma Cell Lineage, Thyroid Gland, Uterus.
What does a “No Cancer Signal Detected” result mean?
The Galleri test looked for a cancer signal and did not find one.
In a clinical study, less than 1% of individuals with a No Cancer Signal Detected result had cancer.4
This result does not completely rule out the possibility of cancer. The Galleri test does not detect all cancers and not all cancers can be detected in the blood.
NEXT STEPS
Continue with any routine cancer screenings your healthcare provider recommends. Do not ignore cancer signs or symptoms if they occur as this could lead to a delayed diagnosis.
Adding Galleri to annual wellness visits can improve the chances of finding cancer early when there are more treatment options. Ask your healthcare provider when is best to test again.



How does the test work?
All cells in your body, including cancer cells, release DNA fragments known as cell-free DNA into the bloodstream. The DNA from cancer cells is different from the DNA of healthy cells. DNA from cancer cells have specific methylation patterns that identify it as cancer. Methylation patterns also contain information about where in the body the cancer signal is coming from.
If a pattern that suggests cancer is found, then the Galleri test result would be “Cancer Signal Detected.” The test then analyzes the DNA methylation patterns in the sample to predict one or two locations in the body the signal may be coming from known as “Cancer Signal Origins.”
Test results FAQ
Your result should be available to your healthcare provider within 10 business days (Mon — Fri excluding holidays) from the time your sample is received at the GRAIL laboratory. Your sample will arrive at the lab 1 to 2 business days after your blood draw.
The Galleri test detected a signal associated with cancer. This result will also include one or two predictions of where in the body the cancer signal may be coming from, called “Cancer Signal Origins.” This result is not a diagnosis and requires follow-up diagnostic tests such as imaging or blood tests ordered by your healthcare provider to confirm cancer.
The Galleri test looked for a cancer signal in your blood sample and did not find one. This result does not completely rule out the possibility of cancer. The Galleri test does not detect all cancers and not all cancers can be detected in the blood. Continue with routine cancer screenings your healthcare provider recommends. Do not ignore cancer signs or symptoms if they occur as this could lead to a delayed diagnosis.
If cancer is not diagnosed after further testing, it could mean that further diagnostic tests are required to detect cancer or the cancer is in a different part of the body. It could mean that no cancer is present, this is called a false positive. Your healthcare provider will determine next steps which may include recommended cancer screening and reporting new signs or symptoms. Ask your healthcare provider if and when is best to test again.
The Galleri test looks for a shared cancer signal across more than 50 types of cancer. The Galleri test does not detect all cancers and not all cancers may be detected in the blood. Recommended routine cancer screening tests such as colonoscopy or mammograms are commonly used and have been shown to reduce cancer deaths. The Galleri test is intended to be used in addition to and not replace these tests and can help increase the chance of early cancer detection. Missing recommended screening or ignoring symptoms could lead to a delayed diagnosis of cancer. Ask your healthcare provider about what cancer screening tests are right for you.
Galleri is a screening test and does not diagnose cancer. Additional follow-up diagnostic tests, such as imaging or other blood tests ordered by your healthcare provider are needed to confirm if cancer is present.
The test does not measure your genetic risk of developing cancer in the future and is instead looking for the presence of cancer at the time your blood is drawn. You may develop cancer in the future. Your healthcare provider is the best person to determine when to take the Galleri test again as part of your wellness screening based on any underlying risk factors.
All results are automatically shared with the provider who ordered the test. If you would like us to share your results to an additional healthcare provider, please contact Customer Service by emailing customerservice@grail.com or calling 833−694−2553 to receive instructions on how to complete a results release form.
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If you have questions or would like assistance
Important safety information
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 “No Cancer Signal 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.
Laboratory / test information
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 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.
- Klein EA, Richards D, Cohn A, et al. Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set. Ann Oncol. 2021;32(9):1167 – 1177. doi: 10.1016/j.annonc.2021.05.806.
- Amin MB, et al. (Eds). AJCC Cancer Staging Manual (8th edition). Springer International Publishing: American Joint Commission on Cancer; 2017
- Beer TM, et al. J Clin Oncol 2021:39(supple 15; abstr 3070) Presented at the American Society of Clinical Oncology (ASCO) Virtual Annual Meeting, June 4 – 8, 2021.
- Based on modeled negative predictive value of 99.4% using CCGA3 sub-study clinical results and SEER cancer incidence rates. Data on file GA-2021 – 0071.