GRAIL to Present New Data at the American Association for Cancer Research (AACR) Annual Meeting
April 26, 2020

Findings Demonstrate Strong Performance of GRAIL’s Multi-Cancer Early Detection Blood Test in Patients with Suspicion of Cancer

High Accuracy in Tissue of Origin May Help Direct and Accelerate Cancer Diagnosis

MENLO PARK, Calif., April 26, 2020 — GRAIL, Inc., a healthcare company whose mission is to detect cancer early, today announced that new data for its investigational multi-cancer early detection blood test will be presented at the American Association for Cancer Research (AACR) Virtual Annual Meeting I. These new data evaluate the performance of GRAIL’s test in symptomatic participants with suspicion of cancer.

Today, the majority of deadly cancers do not have guideline-recommended screening tests available, and as a result, most cancers are detected too late, after they have progressed to late stages when chances of survival are much lower. There is also a high unmet need for early detection in the diagnostic assessment of symptomatic patients who are being evaluated for cancer. GRAIL’s multi-cancer early detection technology can detect more than 50 cancers, with a very low false positive rate of less than one percent, through a single blood draw. When a cancer signal is detected, the test can also identify where the cancer is located in the body (the tissue of origin) with high accuracy. This technology could be particularly useful in directing a more efficient diagnostic workup in symptomatic patients who are being evaluated for cancer.

“We continue to make significant progress in the validation of our multi-cancer early detection blood test, and wanted to assess its potential to drive efficiencies in the diagnostic workup of patients who are showing symptoms,” said Alex Aravanis, MD, PhD, Chief Scientific Officer and Head of R&D, and a co-founder of GRAIL. “These findings show that when our multi-cancer test detected a cancer signal, it also identified where in the body that cancer was located with high accuracy. This is critical information for healthcare providers, and demonstrates the feasibility of our test to potentially accelerate diagnosis in individuals with high suspicion of cancer by helping direct the diagnostic workup.”

These new data represent a pre-specified sub-group from GRAIL’s foundational Circulating Cell-free Genome Atlas (CCGA) study, which included more than 15,000 participants with or without a diagnosis of cancer. In the sub-group analysis reported at AACR, participants being evaluated for suspicion of cancer were classified as clinically confirmed cancer (n=164 in training, n=75 in validation) or clinically confirmed non-cancer (n=49 in training, n=15 in validation). In the confirmed non-cancer group, all training and validation samples were correctly predicted as non-cancer, or 100% specificity.

In the validation set, detection across all stages in the confirmed cancer group was 46.7% (n=35/75; 95% confidence interval [CI]: 35.1-58.6%) at 100% specificity. When renal cancers — which were overrepresented and subject to poor detection at early stages due to low tumor cfDNA fraction — were not included, detection across stages was 59.3% (n=35/59; 95% CI: 45.7-71.9%). In stages II and above, detection was 78.9% (n=30/38; 95% CI: 62.7-90.4%), all at 100% specificity. Performance was consistent across training and validation sets.

For cancers where a signal was detected, the tissue of origin (TOO) was predicted in 93.9% (n=62/66) of samples in training, and 100% (n=35/35) in validation. Of those with a TOO result, accuracy was 85.5% (n=53/62; 95% CI: 74.2-93.1%) and 97.1% (n=34/35; 95% CI: 85.1-99.9%), respectively.

The data are being presented online by David D. Thiel, MD, Chair, Mayo Clinic Florida Department of Urology. The presentation slides will be available at after the presentation.

AACR Presentation Details

Abstract CT291
Lincoln Nadauld, et al. The PATHFINDER Study: Assessment of the implementation of an investigational multi-cancer early detection test into clinical practice
Session VPO.CT07.03 – Phase III Trials in Progress: April 27, 2020: 9:00AM-6:00PM EDT

Abstract CT021
David D. Thiel, et al. Prediction of cancer and tissue of origin in individuals with suspicion of cancer using a cell-free DNA multi-cancer early detection test
Session VCTPL02 – Early Detection and ctDNA: April 28, 2020: 1:40PM-1:50PM EDT

About CCGA

The Circulating Cell-free Genome Atlas (CCGA) study is a prospectively designed, observational, longitudinal, case-control study that has completed enrollment of approximately 15,000 participants with and without cancer across 142 sites in the United States and Canada. CCGA is designed to characterize the landscape of genomic cancer signals in the blood, and to discover, train, and validate GRAIL’s multi-cancer early detection blood test through three pre-planned sub-studies. To learn more about CCGA, please visit

About GRAIL’s Multi-Cancer Early Detection Test

GRAIL’s multi-cancer early detection test is designed to detect cancers in early stages, when the chance of survival is higher than if cancer is detected after symptoms appear. Clinical data have shown the ability of this technology to detect more than 50 cancer types with a very low false positive rate of less than one percent. GRAIL’s test was designed to minimize false positives in order to limit associated harms, including patient anxiety and unnecessary diagnostic workups. When a cancer signal is detected, the test has been able to identify where in the body the cancer is located with high accuracy, an important step to guiding diagnostic next steps and care.

GRAIL’s methylation-based technology preferentially targets the most informative regions of the genome and is designed to use its proprietary database and machine-learning algorithms to both detect the presence of cancer and identify the tumor’s tissue of origin. GRAIL believes its sequencing database of cancer and non-cancer methylation signatures is the largest of its kind.


GRAIL is a healthcare company whose mission is to detect cancer early, when it can be cured. GRAIL is focused on alleviating the global burden of cancer by developing pioneering technology to detect and identify multiple deadly cancer types early. The company is using the power of next-generation sequencing, population-scale clinical studies, and state-of-the-art computer science and data science to enhance the scientific understanding of cancer biology, and to develop its multi-cancer early detection blood test. GRAIL is located in Menlo Park, California and Washington, D.C. It is supported by leading global investors and pharmaceutical, technology, and healthcare companies. For more information, please visit

Kelsey Grossman