FAQs

for Providers about the Galleri® test


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Galleri is a screening test that analyzes methylation patterns on cell-free DNA to look for a unique cancer signature.1 All cells, including cancer growing in the body, shed DNA into the bloodstream, known as cell-free DNA (cfDNA). The Galleri test checks hundreds of thousands of methylation sites covering the most relevant genomic regions in DNA.2

When the Galleri test detects what could be cfDNA from cancer, it analyzes the methylation patterns to identify the tissue type or organ associated with the cancer signal. Based on this, the Galleri test indicates the most likely Cancer Signal Origin that can help guide the diagnostic workup to confirm the presence of cancer.1,3

Learn more about How Galleri Works.

In a clinical study which included 2,823 cancer participants and 1,254 non cancer participant controls, the Galleri test detected a cancer signal shared by more than 50 cancer types as defined by AJCC.2,4

The Galleri test comprises a two-step process: 

  1. The test detects a cancer signal by analyzing methylation patterns in cell-free DNA (cfDNA), which are DNA fragments circulating in the blood. 
  2. The test predicts the tissue or organ associated with the cancer signal, also known as the Cancer Signal Origin (CSO). 

When a cancer signal is detected, the Galleri test applies pattern recognition to compare the DNA methylation pattern in the patients’ cfDNA to the patterns of 18 possible CSO predictions.2 The overall accuracy for CSO prediction is 93.4%.2 In addition, some cancers have other patterns associated with biological information. This Additional Prediction Information may be present in 40% of Cancer Signal Detected results and is 93% accurate.2

The Galleri test analyzes cell-free DNA (DNA fragments circulating in the blood) to detect abnormalities in methylation patterns that could signal the presence of cancer.1 Galleri has higher sensitivity for the deadliest cancers, which helps minimize overdiagnosis and overtreatment of indolent cancers. 

Apart from differences in tumor burden (e.g., stage), cfDNA availability is impacted by a variety of biological and physiological factors that modulate the rate of cfDNA release and clearance, such as tissue perfusion, cell turnover activity, and cell proliferation rate. 

  • Movement of cfDNA from a tumor into circulation can be limited by anatomic location.5 
  • Less aggressive cancers, such as many thyroid cancers, release less cell-free DNA into the bloodstream and are less likely to be detected. 
  • More aggressive cancers, such as pancreatic cancer, tend to release more cell-free DNA into the bloodstream at early stages and are more likely to be detected.1,6

In the PATHFINDER study, the Galleri test approximately doubled the number of cancers detected with recommended screening. Nearly half of the cancers detected by the Galleri test were in stages I-II.7 These detection rates suggest that adding the Galleri test to guideline-recommended cancer screening can potentially increase the detection of early-stage cancers and cancers that lack screening options today.

Learn more about Galleri Test Performance.

False positives occur with any type of cancer screening, such as mammography or stool-based colon screening. A low false positive rate — which can minimize the possibility of false alarms, reducing unnecessary anxiety, costs, and medical risks of unneeded follow-up procedures — is a key component to a successful broad-based population cancer screening test.8 The Galleri test has a low false positive rate of 0.5%.1,7 This means that in approximately 200 people without cancer, 1 person would be expected to receive a false positive result from the test.1 

Learn more about Galleri Test Performance.

Galleri is recommended for use in adults with an elevated risk for cancer, such as those aged 50 or older. Galleri should be used in addition to guideline-recommended single-cancer screenings, such as mammography, colonoscopy, low-dose computed tomography, PSA, or cervical cancer screenings. Use of Galleri is not recommended in individuals who are pregnant, 21 years old or younger, or undergoing active cancer treatment.

Currently, single-cancer screenings play an important role in detecting 5 specific cancers* (breast, cervical, colorectal, lung, and prostate) and have been shown to decrease cancer-specific mortality for the individual cancers that they detect. However, nearly 70% of deaths are caused by cancers that don’t have recommended screenings.4,6 The Galleri test can screen for many of the deadliest cancers that do not currently have recommended screening, including pancreatic, ovarian, liver/bile duct, and others.1,4,6* In the PATHFINDER study, the Galleri test approximately doubled the number of screen-detected cancers.7**

*Assumes screening is available for all prostate, breast, cervical, and colorectal cancer cases and 43% of lung cancer cases (based on the estimated proportion of lung cancers that occur in screen-eligible individuals older than 40 years). Sensitivity in study participants with — Pancreatic cancer: 83.7% overall (61.9% for stage I, 60.0% stage II, 85.7% stage III, 95.9% stage IV); ovarian cancer: 83.1% overall (50.0% for stage I, 80.0% stage II, 87.1% stage III, 94.7% stage IV); and liver/bile duct cancer: 93.5% overall (100% for stage I, 70.0% stage II, 100% stage III, 100% stage IV).

**Cancers detected by the early version of the Galleri test that were confirmed by a diagnostic workup.

The Galleri test identifies DNA shed by cancer cells into the bloodstream to screen for the current presence of cancer and can be done as an annual test. Germline genetic tests look for inherited mutations that increase the risk of developing cancer in the future and are usually done only once.1,9-12

The Galleri test must be ordered by a licensed healthcare provider with prescriptive authority in the state in which they will be prescribing Galleri. This may include physicians, nurse practitioners, or physician assistants.

The Galleri test is currently not included in cancer screening guidelines.

Based on modeled data, adding annual screening with the Galleri test to usual care can potentially reduce late-stage cancer diagnosis.11

The Galleri test is commercially available throughout the United States and in select geographic locations through distributors.

The list price for the Galleri test is $949. Contact GRAIL Customer Service at (833) 694‑2553 or fill out a support request if you have questions about pricing.

A limited number of health insurance plans currently cover the Galleri test. The test represents a significant innovation in cancer screening and coverage with payers will continue to evolve over time. Patients may elect to pay for the test themselves and/or check with their insurer for coverage before requesting the test. 

The Galleri test is now covered for eligible beneficiaries through TRICARE. Prior authorization is required. Click here for more details.

GRAIL offers patients convenient options to pay for the Galleri test. Patients may contact GRAIL customer service at (833) 694‑2553 to learn more about enrolling in a flexible payment plan.

For a patient paying directly for the test in full (patient self-pay), credit card information can be added to the paper Test Requisition Form at the time of order.

Patients can also pay for the test online with all major credit cards (American Express, Visa, Mastercard, and Discover) once their test has been processed by the GRAIL lab. Additionally, payment can be made over the phone by calling GRAIL Billing Support at 858-333-5986 or by mailing a physical check, GRAIL ID and bottom portion of invoice to GRAIL, Inc. at the address provided below:

GRAIL, Inc.
Dept LA 25195
Pasadena, CA 91185 – 5195

Patients may be able to use pre-tax dollars in a flexible spending account (FSA) or health savings account (HSA) to pay for the Galleri test and should check with their FSA/HSA account administrator or insurance company to determine eligibility.

All or a portion of the Galleri test may be covered by some individual employers as an employer-sponsored benefit. Patients should contact their employer to learn whether they cover the Galleri test and to check their availability.

For electronic orders via the Provider Portal, patients will be invoiced via email and/or mail at the address(es) provided on the Test Requisition Form once the sample is received in the laboratory.

Patients should check with their FSA/HSA account administrator or insurance company to determine eligibility.

If you are a returning provider, sign in to the Provider Portal to order the Galleri test.
If you are a new provider, please visit the Order Test page to start ordering the Galleri test.

Specimen requirements include:

  1. Specimen Type: Human Whole Blood
  2. Container: Streck Cell-Free DNA® Blood Collection Tubes (included as part of the specimen collection kit)
  3. Volume: 10mL x 2 tubes
  4. Sample Storage: Ambient temperature (not to extend outside the 1-40℃ (33.8-104℉) range)
  5. Stability: Up to 7 calendar days

Specimen rejection criteria include:

  1. Tubes other than the Streck Cell-Free DNA Blood Collection Tubes
  2. Less than 3mL of whole blood per collection tube
  3. Unlabeled specimens
  4. Severely damaged or dangerously packaged specimens
  5. Specimens with grossly hemolyzed plasma
  6. Specimens submitted or stored at temperature outside of 1-40℃ (33.8-104℉)
  7. Collection date more than 7 days prior to the start of processing


Collection kits should be stored at room temperature. Avoid storing the collection kits in places that experience high or low temperatures like window sills or near central heating vents.

No, the Galleri test blood draw requires no preparation or fasting by the patient. Fasting for other blood draws will not affect the Galleri test results if blood is drawn at the same time.

Test results should be available to the ordering provider about 2 weeks from the date the sample arrives at GRAIL’s laboratory. Typically, a sample will arrive at the laboratory in 1 to 2 business days after the blood sample is shipped. 

In the rare scenarios where a sample fails, you will be notified about your patient’s sample status.

The Galleri test results are shared with the ordering healthcare provider via the online Provider Portal and/or via automatic fax notifications. An email notification will be sent to the ordering provider when new test result reports are ready in the Provider Portal.

If you or a patient would like to cancel a test order, please contact GRAIL Customer Service at (833) 694‑2553 or fill out a support request.

A No Cancer Signal Detected result indicates that the Galleri test did not detect a methylation pattern associated with cancer. In the PATHFINDER clinical study, on average, fewer than 2 out of 100 people with a No Cancer Signal Detected result received a cancer diagnosis (the negative predictive value or NPV was 98.5%).1,7

The Galleri test does not detect a signal for all cancers and not all cancers can be detected in the blood. A No Cancer Signal Detected result does not completely rule out the possibility of cancer and does not predict the risk of developing cancer in the future. Individuals who receive a No Cancer Signal Detected result should continue with all recommended cancer screening options at intervals appropriate for the individual. 

A Cancer Signal Detected result indicates that the Galleri test detected cfDNA with methylation patterns often associated with cancer. In the PATHFINDER study, on average, 4 out of 10 people with a Cancer Signal Detected result received a cancer diagnosis (the positive predictive value or PPV was 43%).7

Galleri is a screening test and does not diagnose cancer. Diagnostic testing is needed to confirm cancer.

If a cancer signal is detected, the Galleri test predicts the most likely tissue type or organ associated with the cancer signal to help guide the next steps to diagnosis.1 The CSO prediction is provided to help guide the diagnostic evaluation needed to confirm the presence of cancer and the cancer type.

Diagnostic tests needed to confirm a cancer diagnosis may vary depending on the reported Cancer Signal Origin and should be chosen in accordance with standard medical practice.1,7 Diagnostic decisions are the responsibility of the treating physician. GRAIL also offers clinical support and resources to help ensure you and your patients are supported after a Cancer Signal Detected result. 

For more information about our clinical support resources, contact GRAIL Customer Service at 833−694−2553 or fill out a support request.

GRAIL offers clinical support and resources to ensure you and your patients are well supported after a "Cancer Signal Detected" result. In the event that a diagnostic evaluation after a "Cancer Signal Detected" result does not confirm cancer, patients may be eligible for a complimentary Galleri retest within 3 – 6 months after the original test result. To initiate a no-charge retest or obtain more information on our clinical support resources, please contact GRAIL Customer Service at (833) 694‑2553 or fill out a support request.

A test may be canceled for a variety of reasons, which include healthcare provider or patient requests, exceeding the specimen stability window, and failure to meet sample quality requirements, among others. For more information on your specific cancellation, please contact GRAIL Customer Service at (833) 694‑2553 or fill out a support request.

Galleri test results can be accessed via the Provider Portal.

For more information about a specific patient’s test result, please contact GRAIL Customer Service at (833) 694‑2553 or fill out a support request.

The Galleri test is recommended for use in adults with an elevated risk for cancer, such as those age 50 or older. The test does not detect all cancers and should be used in addition to routine cancer screening tests recommended by a healthcare provider. The Galleri test is intended to detect cancer signals and predict where in the body the cancer signal is located. Use of the test 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.

The GRAIL clinical laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and accredited by the College of American Pathologists. 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. The GRAIL clinical laboratory is regulated under CLIA to perform high-complexity testing. The Galleri test is intended for clinical purposes.

  1. 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 Sep;32(9):1167-77. doi: 10.1016/j.annonc.2021.05.806
  2. [GRAIL, Inc. Data on file: VV-TMF-59592]
  3. Thierry AR, El Messaoudi S, Gahan PB, et al. Origins, structures, and functions of circulating DNA in oncology. Cancer Metastasis Rev. 2016 Jul 8;35:347–76. doi: 10.1007/s10555-016-9629-x 
  4. US Preventive Services Task Force. A,B,C grade recommendations, cancer, screening. [cited 2023 Oct 23]. https://www.uspreventiveservicestaskforce.org/uspstf/topic_search_results
  5. Bronkhorst AJ, Ungerer V, Holdenrieder S. The emerging role of cell-free DNA as a molecular marker for cancer management. Biomol Detect Quantif. 2019 Mar 18;17:100087. doi: https://doi.org/10.1016/j.bdq.2019.100087.
  6. American Cancer Society. Cancer Facts & Figures 2022. https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/cancer-facts-figures-2022.html [GRAIL, Inc. Data on file: GA-2021-0065]
  7. 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 
  8. Shreffler J, Huecker MR. Diagnostic testing accuracy: sensitivity, specificity, predictive values and likelihood ratios [updated 2023 Mar 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. https://www.ncbi.nlm.nih.gov/books/NBK557491/
  9. American Cancer Society. Understanding genetic testing for cancer risk [cited 2024 Mar 15] https://www.cancer.org/cancer/risk-prevention/genetics/genetic-testing-for-cancer-risk/understanding-genetic-testing-for-cancer.html  
  10. Patel A. Methylated DNA biomarkers and incident cancer in the American Cancer Society (ACS) Cancer Prevention Study-3 (CPS-3) cohort. American Society of Clinical Oncology (ASCO) Virtual Annual Meeting [presentation]; 2023 Jun 2-6. https://meetings.asco.org/abstracts-presentations/218486  
  11. Sasieni P, Clarke CA, Hubbell E. Impact of MCED screening interval on reduction in late-stage cancer diagnosis and mortality. European Society for Medical Oncology (ESMO) Virtual Congress [poster]; 2021 Sep 16-21. 
  12. Schwartzberg L, Broder MS, Ailawadhi S, et al. Impact of early detection on cancer curability: A modified Delphi panel study. PLoS One. 2022;17(12):e0279227. doi: 10.1371/journal.pone.0279227